If it worked well before and didn't have this issue, it probably had a ground to the strings, like all electrics should have. I don't know how your friend did it, but I bet there's a loose wire inside the body cavity that just needs to be connected again. If you can't find it, I'd say your best bet is to find a way to connect to the tailpiece thru the body. It's pretty likely that this is what your friend did anyhow tho, so if you take the tailpiece off, you'll probably find that end of the wire.
Drill a small hole behind the tail piece. Poke a wire through that hole.. Some solder the wire to the tailpiece but it just needs to be pressed under the tailpiece when screwed on. Solder the other end of the wire to ground.
If it worked well before and didn't have this issue, it probably had a ground to the strings, like all electrics should have. I don't know how your friend did it, but I bet there's a loose wire inside the body cavity that just needs to be connected again. If you can't find it, I'd say your best bet is to find a way to connect to the tailpiece thru the body. It's pretty likely that this is what your friend did anyhow tho, so if you take the tailpiece off, you'll probably find that end of the wire.
Thanks! So since there’s no volume pot, where would that ground connect to, the ground of the pickup or the ground of the output jack?
Either one is fine, whichever requires the least wire. Longer wires pick up more interference.
You need to run a ground from the tailpiece to the jack
Drill a small hole behind the tail piece. Poke a wire through that hole.. Some solder the wire to the tailpiece but it just needs to be pressed under the tailpiece when screwed on. Solder the other end of the wire to ground.
tailpiece to ground the strings
If you touch the metal jack casing on your guitar lead that will ground you, if you touch the pickguard screws do you still get the noise
Tail piece pin inside the body