[Stalker61]

You are in a contest to win a million dollars. There are 3 light switches at the bottom of the building (where you start) and only 1 of them goes to the light bulb on the top floor. You have 1 elevator ride up to the top floor too see which switch goes to the light bulb. You can't leave the building to look up for a light in the windows and there are no stairs. The only way up is the elevator and you can ride it up, once. Which switch is it?