>>/44901/
At the moment I can't reach pal, I'll try later again.
It sounds like the switch. I dunno how a switch can broke in such way.
Do you remember when you turned the electricity back on for the first time: was the bulb light at that moment (or when you walked into the room the first time)?
Maybe until the problem is solved you might wanna take out the bulb (switch the fuse off for the whole flat first ofc).