@YT,
first you should enter the room where the switches are set up...
then trigger one of the three switches by your choice, let it on for about 3 minutes or more.. then switch it off.. then trigger another switch and leave the room..
enter the room where the light is placed..
the bulb where the light is on is the owner of the switch you left on.. and the light bulb that is still hot but is turned off is the owner of the first switch you trigger... and the third bulb is the owner of the switch that is not triggered...
right????