Ya know, that does't surprise me!Likely, it is. I was a Pete’s place a few years ago, when he was on his single coil kick. Bad hum in one room. He told me about hiring an electrician and spending a day trying to track down the problem. It turned out to be that little box the water company added.
I don't know if there's anything I can/should do to remedy the situation, other than turn the storage room into a recording area (It's actually larger than my studio, so I could do it...but...I dunno, gotta stop somewhere).