Does anyone know why switching lights on/off would cause Windows to play the "hardware disconnected" sound?

Yes. The printer (for example) which already takes a lot of power, loses it monetarily when the lights get switched on and off.

This is a sign of too many things plugged in on a single circuit. If you can, separate/divide ths stuff you have plugged in so it isn’t all on one single wall plug or one single circuit.

@elbanditoroso I was going to say the same thing. :)

@ragingloli If you can even go so far as wiring your printer in another room or at least charge your cameras and phones somewhere else that could help. Folks have a habit of charging everything along with their computer set up.

@DWW25921
I already tried putting some devices on another outlet when turning on the power strip caused the fuse to trip, but unfortunately it seems that all the sockets in my flat are on the same circuit.

I don’t know your answer, but I know that turning on the porch light sometimes causes momentary interference in playing a DVD in the living room.

When this house was built, most of the devices that we now have plugged in had not been invented yet.

A “fix” might be to buy a battery back-up. It will keep the voltage from sagging on the printer and the PC could be plugged in too.

It could be that the circuit breaker wasn’t built to handle the load, or it’s gone bad.

I had to get a breaker replaced because it would trip when I tried to use the air conditioner.

@ragingloli That’s a bummer. I’d get some sort of backup power supply.