Different sort of noise

[Yomanze]

So a late night at the office, back at home and the family is out, so a super-quiet evening. Each time I switch tabs in my browser, perform tasks etc. I hear some noise like when a hard drive moves (except my laptop is solid state), which I eventually narrowed down from paranoia to a lamp plugged into the same outlet at my laptop charger, which together were doing some weird modulation that amplified the processing noises of my laptop so that I could hear it. Very clearly when I opened documents and did stuff it was heard on the plug socket! EDIT: nope, can still hear it with the lamp off.

I should have just gotten an official charger to replace my old one, or my wiring around that outlet is knackered, maybe random circumstance, but it does make you think.