An electrician added a wall outlet in a room. He ran the wires from a switch box in the hall that was never used, but had incoming and outgoing wires. Later, I tried it, and a lamp worked fine, but a computer would not. I tested the outlet, and the tester showed that the hot and ground were switched. I went to the switch box. He indeed connected black to black, white to white and bare to bare. I tested with my voltmeter, and it turns out that the bare wire going into the switchbox is actually hot, and the black is ground.
Would I be asking for trouble if I just switch the wires in the box so that the outlet is correct? I haven't been able to successfully trace it back any further to find where the wires got reversed.

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I tested with my voltmeter, and it turns out that the bare wire going into the switchbox is actually hot, and the black is ground.

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How do you know that? From what you have said I think you are misunderstanding what your meter readings are telling you.

I get a 120 volts reading when I touch ground and black and when I touch ground and white. I get nothing when I touch black and white.

Nothing sounds logical here except the 120 between the black and ground . Are the wires at the outlet under the proper screws. How many cables are in the switch box.

If, at the switch box, there is only one cable, with black, white and ground, that is a switch leg. There is no neutral at the switch.

If there is only one cable, with black and white both connected to the switch, and the electrician connected black to black and white to white as you say, then with the switch in the off position the lamp plugged into the outlet would burn but so would the ceiling light. I am assuming the switch controls a ceiling light. Both lights would burn with the switch in the off position but only at half brightness. With the switch in the on position the ceiling light would burn at normal brightness but the lamp plugged into the outlet would not burn.

That also means that your meter would not show voltage between the black and white with the switch on. It would show voltage with the switch off.

I can't quite imagine an electrician making that error.

I know it doesn't sound logical. The wires are under the proper screws.
There were two 3 wire cables going into the switch box originally. One is the one described above. The other is not connected and goes to a second switch at the other end of the hall (confirmed by continuity check). There are no other cables in that switch box.
The original idea was that these two switches, and a third on the porch, would control a light on the porch, but it was never finished (wonder why!). The third switch box has two 3-wire cables going into it, but neither carries any voltage.
The hole in the wall where the light would have been has 4 cables sticking out of it. 2 are without voltage. The other two are connected at the black and white wires, but not the grounds. The black wires test hot. The ground wires do not.
I hope my attempt at describing this mess hasn't confused you more.

This is going to take some thinking.

How about describing the wires in the ceiling, the number of cables and the kind, 2 or 3 wire. The number of cables in each switch box (I will assume they are all 3-wire). Confirm which cable goes from which switch box to which switch box or the ceiling. Label switches 1, 2, 3. Label cables A,B,C, etc

You can confirm which cable goes where if you disconnect everything and then connect two wires together. Then check for continuity at other switch locations. In other words connect the black and white together at one switch then at some other switch you should have continuity between the black and white.

Do that an post back and we should be able to figure it out. Its late in my time zone, but I will check back early tomorrow morning.

Yeah, the house was built in "82 and he never finished it. I appreciate all the time you've put into this, but back to my original question. Would I be OK to switch the wires in the switch box - ground to black and vice-versa, to see if the outlet will then work properly?

I'll work on it when I can. Thanks again. Goodnight.

So, far I agree with Harold's assessment. Here are some 4-way switch diagrams: 4-Way Switch Wiring Diagrams | Easy to read wiring diagrams for do-it-yourselfers

A reminder, is something that can annoy you and play tricks on your voltmeter is the load, if any, connected. The voltmeter measures the other end as though it's a wire. Toasters, light bulbs and computers would act differently as a load. A toaster is a low resistance. A light bulb is a current dependent resistor and a computer is a complex load.

Since I started thinking about this more globally, I think I may have been mislead by what the original builder of the home said to me. The switch box I'm trying to tie into may NOT be part of the circuit I described. You have to understand that whoever did the original wiring in this house never finished, and I believe left me with some significant issues. There are a number of other junction/switch/outlet boxes with unstripped cables in them. I also have a couple of switches that do nothing but trip a circuit breaker when you flip them. I have them taped off.
So, I'll do some more investigation and get back to you. Thanks for your input so far!

I can appreciate what you are saying. I recently had to install switches and outlets where someone else had pulled the cable. I spent a lot of time verifying how the cables were pulled because I could not trust what I was being told. The person made an error at a 3-way switch location, he connected the switch leg to the power source. He added a second outlet next to an existing outlet. For reasons unknown he pulled a cable from another circuit instead of simply adding a second outlet to the first. He needed an isolated ground at one outlet and pulled 3-wire back to the panel. His plan was to use the red wire as a ground. Why do that if you are pulling back to the panel.

It took hours to figure everything out and only minutes to actually do the work. And that was only 3 circuits.

Be patient, trace each circuit, verify (and label) everything. Only when you understand everything can you confidently make you connections.

As to your original question, I don't think any one could say what is safe at this time. You could open the panel, unless you find a bare wire connected to a breaker, the ground wire at the outlet is not intentionally hot. There may be a short some where that is supplying voltage to the bare wire if the bare wires are connected or grounded.

Thirty years and the house is not finished? Person is almost as slow as I am.

OK, here's an update.
I traced everything I could. My hunch was correct. The circuit with the light boxes on the porch is separate, despite what the original owner told us.
So, I'm back to the original switch box I tied into for the outlet. I could not trace it to it's source. I think it was another unfinished light fixture that was in a cubby in a wall which we have since drywalled over when installing A/C vents. I get what you said now about it being a switch loop. But the ground still shouldn't test hot, right? I'm thinking I should just disconnect the outlet and find another source for it. What do you think?

Could you post an update? Sorry, but I missed your last posting. I usually check all threads to which I post but somehow missed this one.

That's OK, Harold. I appreciate you taking the time for me. I gave up on using the switch wires. When I get the time, I will look for another source to tap for the outlet. Thanks again!

Rereading your original post, you said that the bare wire in the switch box was hot. Is that correct? Is that switch or could it have been at one time, a 3-way switch?
If so, someone could have tried to install a set of 3-way switches, the now covered up location being the other end. People have been known to do that with 2-wire cable using the ground or bare wire as a conductor. That could make the ground hot.

Yes, the bare wire is hot. There are 3 wires. Black to white - nothing. Black to bare - 120 V. White to bare - 120 V.
There are two 3-wire cables in the switch box. One is the one I've described above (the one the electrician tried to tap for the outlet). The other I traced (by measuring resistance) to another switch box at the end of the hall. There are no other cables in that box. I don't know what they are supposed to control. There are several possibilities, as there are several fixture boxes/outlet boxes/other switch boxes that were never finished.

OK.
So you do have a 3-way switch set up. Since we don't know what the switches control, lets eliminate them for the moment. We also don't know why you have 2 3-wire cables in the switch box where the electrician made his connection as opposed to a 2-wire and a 3-wire cable. There are a couple of reasons that might be, but we don't know why right now. Nothing explains why the ground is hot except that there is another problem some where else.

Just for grins, check the outlet for operation with different switch settings. In other words plug a lamp in the outlet and then start changing switch settings. There is probably a certain combination of settings where the outlet works and a certain combination where the outlet is dead. That might explain why the lamp worked and the your computer didn't. A switch got changed. This might provide some information or it might not.

After doing that, disconnect every thing in the first switch box and remove that switch. Check for voltage between the black and white, between the black and ground, the white and ground, and between the red and black.

Check all outlets in that room, both top and bottom, to see if they are live.

Sorry, I forgot you said that the other switch was removed and covered. Just disconnect and check voltage and outlets.