Hi all, I am hoping someone can answer this question. I am in the middle of filling out a questionnaire for a new insurance policy for my Mom's house and they ask what type of electrical wiring we have. I have no idea! It's an original Levittown Pa home built in 1955 with no real improvements done electrically, save for a new breaker box. They give us these choices: Romex, Aluminum, Knob and tube, Bx or "other". Now my Mom says she is sure it's not aluminum but how do I figure out exactly what type it is?

Any light you can shed is greatly appreciated as always.
Thanks to all who answer!

No way for anyone here to know.

If you send some pictures we can determine what type of cable you have.

To confirm if the actual wire is aluminum or copper will require a device, switch, outlet, or the panel opened and look directly at the bare conductor.

This can be dangerous if your not familiar with working with wiring.

You may be better served paying a service call to an electrician to help with this questionnaire.

Oh yeah, If you have an attic or unfinished basement, you may be able to see the wiring.
As above, any photos will help.

Probably in 1955 it wasn't Aluminum. The actual wire is Aluminum and not copper colored. Requires an inspection at the main panel (Circuit breaker box). It's possible that some circuits are aluminum like a stove.

Knob and Tube. Doubt that too. This wiring has a bunch of insulators supporting the wire and the wires normally run in parallel with each other.

Bx: Possible. These are spiral shaped metal tubes carrying wires. The best place to inspect is the outside of the main panel.

Romex or NM-B: Romex is a trade name. You should see these designations on the cable. The cables are rectangular about 1/4" x 5/8". Modern cables hava a plastic insulation. Older houses may have a cloth-like grey insulation. This is most likely. Again watch the wires entering the main panel.

The only real cautionary note is the removal of the cover of the main panel. That's the concern.

Thank you to all who posted.

This practice should never be done:


You might want to consider removing several receptacles and check the wiring there [Wear leather gloves so that you can handle the live receptacle safely].

This is so wrong for so many reasons.

Even thou anyone can request that bad, unsafe advice be removed, I feel the need to let it be known to never handle Live parts with protective gear that is not rated for the job.

This advice is just plain irresponsible, and dangerous.

The power should be off for any work done.

TK, I'm curious. Are you saying that you never work on live circuits?

Also, did you happen to notice that no one told the original poster to turn the power off prior to removing the main panel cover?

In one sense this is a DIY site, so advice needs to ERR on the good advice side. In the other case one might have to define "LIVE". Yes, the circuits have to be LIVE to troubleshoot them. Have I taken covers off "LIVE" things, yes.

The nasty ones in a commercial setting requires keys to operate the equipment and a separate set to open the HV side of the equipment. Then door safety switches must be pulled to allow the eqipment to operate with the door open. In many cases, I'll make the connection and then turn on the equipment. We are talking 10 KV at 1 Amp here.

A main, sub panel, or even a motor starter. Is it LIVE. Answer is yes, BUT I know what parts are SAFE, if I'm replacing a motor starter, you don't have to kill power at the panel, but it has 3 phase power for say a 5 HP motor and all the nasty power is at the top.

Removing outlets on a live circuit, is potentially dangerous to the other connected equipment due to to transients that may develop. Depending on the energy in the circuit nasty things like fused hot screwdrivers can happen.

You have to act responsible, use the right protective equipment and minimize the effect on the rest of the plant/residence.

Circuits in a residence that you need to protect are security, freezer/refrigerator and sump pumps. The security system might call the alarm monitoring company that he power is out. The freezer/refrigerator can be without power for a while. The sump pump might flood.

How did you come this this conclusion?


TK, I'm curious. Are you saying that you never work on live circuits?

Reading between lines again?

I have been doing this work for over 30 years, and of course I have and will need to work on live circuits and parts.

I know what I am doing.

And sure I have gotten shocks, no big deal for me. But of course, I realize I am living on borrowed time. All it takes it one shot across the heart, at the right milliamp of current flow, and I am DEAD.

And I, as is anyone that works with electricity, is now under strict OSHA and NFPA 70E rules about working on live parts.

To tell a layperson that is trying to fill out a questionnaire to grab a live receptacle just wearing leather gloves, and everyone else reading this, is wrong.

They certainly do not know how to handle live parts, and telling them to work on live parts and they end up using a pair of old work gloves that may have holes, moisture, oils, and metal shavings is dangerous.

Any work on live parts must be done by a qualified person that will be wearing the proper protective gear.


I suggested that an electrician be called in to help with the questionnaire.

You explain how to handle live parts with the wrong PPE.

I also mentioned that the power be off for ANY WORK DONE.

I am done debating this issue.

I am also done pussyfooting around any questionable advice.

Any future bad advice I see will be reported, through channels, to the administration of this website and it will be up to them to decide how to deal with it.

I actually change switches and recepticles out with a Leatherman. The trick is, disconnect ground first and connect last and remain Isolated.
I think leather with sweat would be conductive, Rubber works well.
On this site, I try to remember to tell poster to turn off power. I have no idea of their capapibilities. There are something's I would do, I would not recommend to others.