High pitched background noise

[Jenasaurus]

I often sleep with a fan on as cant sleep when its silent and the flat has a lot of activity so not often quiet. Well its now quiet but I can hear a high pitched continuous noise, its very odd, I have heard of something called Tinitus but this seems to be a noise with a real cause, just not sure where from. Anyone else hear high frequency noises but not have tinitus. It appears to be changing in volume too.

I have tinnitus and would know if was tinnitus as it is a noise inside my ears. Not sure if it is the same for everyone.

If you don't have tinnitus can you narrow the noise down to one room, I would methodically work around every electrical device you have and unplug/switch off, at the wall as a faulty electrical component can make this type of noise

I can hear electricity. It’s normally a charger left plugged into the socket but not in use. Or my wardrobe door is slightly ajar...enough to hear the lights but not so they’d actually come on.