Fair experiment with unfair coin!

The puzzle is simple to state: You are given a biased coin with 60% chance for getting heads and 40% chance of getting tails while tossing. Design an experiment with two equally likely outcomes using the coin.

Think out of the box!

2 rooms, 1 light bulb in one room and the other room has 3 switches out of which only one of the light bulb switches on/off. The rooms are not viewable from each other. You as a single person has just one chance to find which switch operates the bulb. How can this be done?