Electrical – Identify neutral and ground, when no color code is present

electrical-panellightingpower

I have a nasty situation in my new apartment: someone (previously), when installing light switches must have randomly connected 3 wires, without giving a respect to a usual color coding.
Now I have:
red, yellow-green, white.
The problem is, when you turn on the switch, yellow-green (which is supposed to be ground), becomes hot. So in order to properly attach my lamp I need to know which of two remaining is ground and neutral.
I don't want to go with "trial and error", i.e. attach to some position and see if you protection will be blown out, then swap, as this may be a dangerous option, when (and this can happen), a neutral gets disconnected at the switch, and not the hot one, which will all lead to a happy burndown. I don't want to take chances.
What should you do?

Best Answer

Easiest way to double check this before wiring anything, just open up another light/receptacle box, or even the switch. See what wire coloring the installer used throughout. Hopefully he stayed consistent. You could also open the panel and see what wire color terminates where.

If this is an individual occurrence, you should be able to see at least what was used for ground in the switch that's wired to this light. Even if the whole apartment wasn't done the same, this circuit might be.

It's a good place to start, let us know what you find.