I am attempting to install a simple, pull-chain light fixture in the ceiling of my entry hallway. A similar lamp was once in this location, but all that remained when I moved in was a single, disintegrating, disconnected socket and a mess of wires. I hired an electrician to sort out the wiring for me and now wish to install a new lampholder socket myself. The 20-Amp branch circuit wiring leaves the breaker box, enters the hole in the ceiling where the lamp will be installed, and is pigtailed (with a wire nut) to wire that continues on to the rest of the circuit. The wire feeding the lamp will need to join this pigtail. (Incidentally, the existing wiring is all aluminum.) My question is two fold:

a) what gauge of solid copper wire do I need to use between this pigtail and the lamp socket? Would it be 12 AWG that is rated for 20-Amp environments, even though the bulb will be a simple 40w/120v Edison drawing 1/3 Amp, at best? Regardless, I should use an AL/CU wire nut to complete the pigtail, correct?

b) Given the answer to a), does any manufacturer make a simple socket w/ pull chain that is appropriate for this situation. My attachment point is currently a 1/8 IP nipple that is joined with a hickey to the 3/8 IP fixture stud. Most lampholders that I see in the stores say they can't accept anything larger than 16 or 18 AWG stranded copper, and don't specify whether using them in a base-up configuration would pose a safety hazard. The closest thing I have found this far is this offering from Leviton:
19980-M > Standard > Shell Lampholders > Incandescent > Lampholders > All Products from Leviton Electrical and Electronic Products (http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=5392&section=10188&minisite=10026)

Thanks for any and all advice!

I'll start with a dumb question. Why a pull chain? Why not a permanent fixture and wire a switch loop back down the wall. This would really be easy if you have access above the ceiling. Code requires a switched fixture or outlet so you don't have to wander around in the dark looking for a pull chain.

Thanks for your reply -- there are a couple of reasons I'm opting for a pull-chain fixture rather than trying to create a link to a wall switch. First and foremost, I'm renting (yes, due to the peculiarities of NYC real estate, renters often find themselves performing this sort of work on their apartments). Secondly, the apartment dates from 1940 and the walls and ceiling are plaster, which would make patching up after such an operation expensive and time-consuming.

As a renter, I'm simply trying to add a light (as in, a single bare bulb) in the hallway with the least cost and hassle. While current code may demand a switch, all I can afford is a pull chain (and a pull chain is presumably what was there way-back-when). I just want to make sure I use the socket, wiring, and connector style (AL/CU) that is appropriate for the job. Since a picture is worth 1000 words, here is a photo of the current situation:
https://picasaweb.google.com/lh/photo/Gk2yTYOmYNwTfwkMDxDSUOmiBKOUYQSo7N0UhYaA3xw?feat=d irectlink

Great picture but the wiring is sure scary. Ok so no ground I can see. Existing ceiling pattern looks like 8-9". Well, here's what i'd do. Remove the nipple. In the lighting dept. at HD or Lowes, you can buy an ornamental ceiling or fan base, plastic foam, white, about 12", has an ornamental edge. Since it's plaster, there are lath strips in the ceiling. Screw the base to the ceiling after cutting a 2-3" hole in the base so the wires can come through. Buy a pull chain fixture-$3- that has a white plastic base and pull chain already attached. Pigtail a small piece of wire to attach the house wire to the light base and then screw the light base to the ornamental base. You might need screw anchors or long wood screws to attach to the lath or small toggle bolts. As far as the wiring, are you sure it's AL? Looks like CU or CU clad. THHN 16 AWG is fine to use for lighting fixtures, you'll only need a couple of ". All non permanent lighing fixtures are factory wired with 16 or 18AWG and they are connected to 14 or 12 house feed. I'd also tape up what appears to be some abraded wire cover-far right wire. If this is original wire, it's CU. Send us a picture when you're done.

Yes, when I first took a look behind the existing 6 3/8'' canopy (weird size, as I've come to realize -- it's pictured here: https://picasaweb.google.com/lh/photo/VBzx8DAp-wGuFOjLCMNg_-miBKOUYQSo7N0UhYaA3xw?feat=directlink) the mess of wires was inpenetrable, which is why I gave up and had an electrician figure out what was what. Thanks for the correction on the wiring material -- both electricians that I've had look at the place seemed to concur that the wiring was aluminum, but after snipping the end off one of the wires (in a nearby outlet) it does appear that it's actually tinned (aka plated) copper, which would make sense as it's original to the 1939 construction (from what I've read, aluminum was only used between 1964 and 1973). Give that it's tinned copper, what are the odds my branch circuits are knob and tube?

Anyway, back to the original question: I'm not sure what you mean by an ornamental ceiling base. Something like this?: 9726-C2 > Outlet Box Mount > Incandescent > Lampholders > All Products from Leviton Electrical and Electronic Products (http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=8731&section=10185&minisite=10026)

I'm sure there's lath up there somewhere, but with that mad tangle of wiring clogging the opening, I can't see it. My idea is just to use the existing IPS nipple, and attach something like this: 95065 > Pull Chain > Incandescent > Lampholders > All Products from Leviton Electrical and Electronic Products (http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=7880&section=14078&minisite=10026)

Rig it up with #16 AWG, then use a bit of plaster or caulk to reattach the canopy to the ceiling, with my new socket popping out of the middle. Can it be that simple?

I should add: the reason why I'm asking about knob and tube is because I read that wire was tinned "because all joints were soldered back then and tinned wire was a lot easier to solder. The wire was rubber coated and cloth covered" The three wires composing the HOT are indeed soldered together, not pigtailed... :/ Just to add to the fun, as you noted earlier, there is no ground.

Yes, that would work. I was trying for something a bit more "elegant". You have the old canopy, that's what I was suggesting to cover the space on the ceiling, just didn't have a good grasp on the terminology-it comes with age(old age that is). You could also try a light kit for a fan. Some of them have a 1/8 pipe fitting hole with a cap on the end. Some of your wire does look like K&T but you could look in the basement for that type of wiring. No ground with that. Here's another option. Get a pendant light, drill the old canopy to accept a single pole pull chain switch and attach it to your ceiling. Yea, it would cost more but you're in NYC right! Skip the pastrami or the reuben for a day or 2, make your own coffee and it's paid for. AND, you could tell them "my consultant in Atlanta suggested this!!"LOL Brian

Thanks Brian -- unfortunately, my blood pressure has meant skipping the pastrami for years, haha. I'm simply trying to restore what I imagine was there before -- a bare A19 bulb hanging upside-down from a socket, with a pull-chain to operate. If my landlord wants something more elaborate, he'll have to pay for that himself.

As far as attaching the socket to the pipe, it seems like a hickey is the only option (a socket cap would only work with the hollow 1/8 IP of a traditional table lamp, not the solid 1/8 IP here, because the wires wouldn't have anywhere to go, right?) I can't find a socket with a pull-chain and a hickey (probably because, as you indicated, pull chained ceiling fixtures don't meet current code, so there's no reason for the manufacturers to make them attachable to a fixture stud), so I guess what I'm going to have to do is get a keyless socket that can attach to the pipe:
http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=5447&section=10183&minisite=10026

and then screw a pull-chain adapter into it:
http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=303741&section=11769&minisite=10026

Every adapter I see has two outlets in addition to a socket... not sure why that is. Anyway, it's far from an elegant solution, but it's the only way I can see to attach the socket to the pipe AND have a pull chain control.

Just to clarify, my understanding is that this type of lampholder won't work in a ceiling, because the wires won't have anywhere to go once you screw the socket cap onto the solid pipe:
95065 > Pull Chain > Incandescent > Lampholders > All Products from Leviton Electrical and Electronic Products (http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=7880&section=14078&minisite=10026)

Suggest that you get a strap and bulb holder as shown. Screw strap onto threaded pipe. Add short 12 gauge pigtails to existing wires using wire nuts. Attach pigtails to bulb holder. Attach bulb holder to strap.

Thanks -- what I think I'm going to do is take the existing canopy to the store and see which one of these options will work with it. Hkstroud, if I can install one of these lampholders with the porcelain surround and the strap, and cover it with the existing canopy (with a hole drilled in it to allow the pull-chain through), I'll do that. Otherwise I'll probably attach a keyless socket directly to the pipe, reattach the canopy, and then screw a pull-chain adapter into the light socket. Basically, I need to be able to use the existing canopy, because otherwise I'll have to fashion some sort of ceiling medallion to cover the rest of the existing hole, which -- at 6 3/8'' -- is wider than the 4 inch diameter of the porcelain lampholder's surround. One of these porcelain fixtures, with all of their notches and cutouts, surrounded by a faux plaster medallion, would not look good, I'm afraid.

As far as the wiring, I think I'm going to opt for 12 AWG as you suggest, hkstroud, because, while Brian (ma0641) says 16 or 18 AWG would be okay, I don't totally understand the implications of using smaller wire to tap into a 20 amp circuit (because this light sits directly above my front door -- and only means of egress -- I do not want to run into any problems with overheating wire).

As far as wiring goes, while a 12AWG pigtail is correct, I have never seen a home ceiling mount luminaire(fixture) with factory installed 12AWG, it would have come with either a 16 or 18 AWG wire already attached and you would have connected those wires to your 12AWG anyway.. PS. Medallion! That's the word I wanted to use last night!

I appreciate all of your comments and suggestions. My budget and level of expertise are both low, so I need all the help I can get! When I get things finished, I'll post a picture.

Sorry, thought you were looking for the very basic. Remember all this stuff has to be UL approved. You can't modify things to make them work.

Maybe you should consider something like this. It doesn't say explicitly, but I think it is battery powered.

Cordless Ceiling/Wall Light with Remote (http://www.gadgetshack.com/cordless-ceiling-wall-light-with-remote.html)

We are glad to help. And you can help HK and me us by checking "yes" is this helpful! Thanks !

Hello all -- Well, a month later, the project is finished. Here's a picture:
https://picasaweb.google.com/lh/photo/PgSZ808CBTGow7JjPxAmiumiBKOUYQSo7N0UhYaA3xw?feat=d irectlink

I mounted a standard porcelain pull chain fixture (using a strap and 12 gauge pigtails), then drilled a hole in the old canopy (for the chain) and added a rubber gasket to its rim for extra depth (I couldn't mount the porcelain fixture deep enough in the ceiling to use the existing canopy without modification). Thanks for all of your advice and pointers!