3 LIGHT SWITCHES LIGHTBULB RIDDLE

A windowless room contains 3 identical light fixtures, each containing an identical light bulb or light globe. Each light is connected to one of 3 switches outside of the room. Each bulb is switched off at present. You are outside the room, and the door is closed. Before opening the door you may play around with the light switches as many times as you like. But once you've opened the door, you may no longer touch a switch. After this, you go into the room and examine the lights. 
How can you tell which switch goes to which light?

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ANSWER - WILL BE UPLOADED SOON

SWITCH 1-1 BULB
SWITCH 2-3 BULB
SWITCH 3-2 BULB