If you can leave the door open.......
Turn on two lights. Go into the room and unscrew one of the light bulbs. Go back out and see which switch you have allready turned on turns off the light that is still on. That solves two bulbs, the last is found by elimination.
Turn on two lights. Go into the room and unscrew one of the light bulbs. Go back out and see which switch you have allready turned on turns off the light that is still on. That solves two bulbs, the last is found by elimination.