I don't think this is perfect, but it should work. Go into each of the three of the light switch rooms and turn on one for a short period of time, one for a medium period of time, and one for a long period of time. Then turn each one off as you leave the room. Then go into each light room and test the temperature of the light bulbs. The cold one is obviously the one you didn't turn on. The other three should have hopefully noticably different temperatures. You can then match up the rooms.