ok here's the thing, I know NOTHING about electricals so don't blame me if I look stupid or I make you look stupid trying it.
1) check your amp grounding. if done so.
2) check your guitars, if the guitar tech says it's okay.
3) guess what, most likely try a different power socket, whether it's in your
bedroom/kitchen/living room etc.
and one more thing, I often get this problem with recording single coil-ed guitars/bass.
I've tried using my wrist-grounding band , it doesn't work. so tell you what you should try to see if you're facing "my" problem.
1) get aluminium foil. twist it until it looks like one big fat wire. make sure you don't break it.
2) so now you got an aluminium wire of both ends. A and B.
a) attach End "A" to the guitar's string at the headstock. any metal part of the guitar will do. make sure it's secured.
b) hold End "B" with YOUR right hand's thumb and index finger.
3) now try "touch" the fret/strings and see if that electric buzz still happens. i am confidently guessing it's gone now.
you must be really happy and thinking "what next? I need my left hand to play on the frets and right hand to strum". as I was saying , I know nothing about electricals, this post of mine isn't an answer, but both answer and question. as you've probably noticed in 2b) I said "YOUR" hand because this doesn't work if you get a friend to hold it for you or if you hold the end with your lips or somethin. it'll only work with your fingers or guess what : Toe! (I haven't tried penis yet, but I'm sticking with the toe.)
so at the end of this post, my question is : it's not me (even though I was badly electrocuted when I was 10 years old. i can't be dispersing electricity now) because the guitarist I was recording had that problem.
it's not his guitar (he claims if he plugs into his own amp or jam room it's okay).so highly likely it's got to do with the grounding of your room.
if not, the guitar.if not. the amp.
I use this aluminium>frethead-guitar-string>to>toe method as a temporary solution for the bands I record when this shit happens.
thank you and eat well sleep well, looking forward to any guys who's well versed in electrical stuff to post.
10¢ worth.