I've been doing some reading on this forum, learned quite a few things, and this is my first post!
First off, I am decent with DC circuitry but a total noob when it comes to home (AC) electrical. Also, English is my second language so I hope the terms are right and clear :)
I'm having an issue which will require a qualified electrician to fix, but I would really like to understand what and how it's happening.
Very old house, wiring certainly not up to code. I wanted to replace an outlet in the garage that's causing slight shock when using a metallic power tool and touching my metal work table. Before going through I did verify using an outlet on a different circuit and the the issue is not present. After switching off the panel breaker and making sure the power was off I removed the outlet and did not see any damaged wire that could make a short or cause an issue. I only realized that it was a mess since there were 6 wires plugged to the terminals of the outlet, white and black mixed together, no ground wire -apart from a connection that was added to one of the light switches-..damn
This outlet connects to two light switches (three way) and the circuit bringing the power to the outlet also powers a part of the house (wow..).
I installed a GFCI outlet to make things a BIT safer, it works, but I still have the same issue, power to ground (?) -bought a non-contact circuit tester to make my life easier, yay-. Took the time to check with the tester and ended up with weird results;
The outlet box itself, both switches box in the garage, are all HOT (they all make my pretty accurate tester beep) How can this be possible? Two boxes have a cable with ground connecting them, I could understand, but the third one use a 2 wire cable connecting it to the outlet.
For now the breaker remains off, I need to get a quote from a QUALIFIED professional, but I'm puzzled and would like to understand the issue.
Thanks for your time, and sorry for the long read!!
Update; Took some measurements yesterday after work at the outlet;
Hot(blk) to box .2V Return (white) to box 1.0V Hot to return 120v (118~)
Obviously box is not grounded.
Used an extension from a recently installed outlet with working ground.
Hot to grnd 120v return to grnt 0v box to grnd 1v
Interestingly enough, without anything plugged in the outlet, if I measure voltage between working ground and outlet housing/cage (where it screws to electrical box) i get Ov, but if i plug something in, i get 36V!
Also, I realized the light fixture in the ceiling is wired wrong (reverse polarity).. Unplugged this circuit from the outlet connection but I still have the shock hazard issue.
Sorry I cannot upload pictures as they are over 2mb and cant edit at the moment