noahfor

I know there is like a daily or weekly riddle, but it's hard to find for me, so maybe if they were all in one thread. If you get the riddle correct you post one.

Here:

There is a room with a lightbulb inside, outside the room there are three switches, only one controls the light. You cannot see in the room or any light escaping the room from outside. How can you find out which switch controls the light if you are only allowed to enter the room one time?