Hi Squeak,
there's so many threads running you might have already answered this. May be a bit of a dumb question, but did you actually unplug everything in the house ( not just switch off) and see if it still did it ?

best wishes
Rikki
_________________________
best wishes
Rikki 🧸

Korg PA5X 88 note
SX900
Band in a Box 2022