Okay, so an ordinary room. With a light. Operated by a switch rather daftly placed where you can't see into the room. Presumably you don't have a handy portal gun either. And also, presumably, there aren't other doors into the room other than the one you've already stated can only be opened once.
So, different questions:
The switches that do no operate the light are connected to nothing? Or are the television and microwave postulated actually connected?
If there are both a television and microwave, can they be turned on and heard from the location that the switches are activated? The microwave should make a buzzing sound and the television, at the very least, make a loud hissing sound...
(Probably barking up the wrong tree, but giving it a whirl nonetheless.)
So, different questions:
The switches that do no operate the light are connected to nothing? Or are the television and microwave postulated actually connected?
If there are both a television and microwave, can they be turned on and heard from the location that the switches are activated? The microwave should make a buzzing sound and the television, at the very least, make a loud hissing sound...
(Probably barking up the wrong tree, but giving it a whirl nonetheless.)