Ok, well I think I have it then.

Leo is an awesome guy, so he gets chosen to be the leader because he was the first person to go inside. He tells everyone else that when they go in they must turn the light off if it was on when they entered. Once you turn the light off if you are chosen to go again you must not touch anything. If you come into the room and find the light off you do not touch anything. Every time this awesome guy that happen to be called Leo walks in he turns the switch on. He keeps count of  every time he does this and when he gets to 99 he wins.

I still stick with suing the government for trauma and distress.

Just realised you can switch on and off in my answer and then that awesome guy wouldn't have to go first.

is light off always when new person enters room?

If the light is on, no one touches it except Leo. When Leo touched it he counts one.

When the light is off if anyone goes in there they must turn it on. However if they get chosen again and the light is off they do nothing.

(This is if everything is switched from my answer)

Leo is correct, however everything is reversed. The special guy always turns the light off.

So.

Basically if the light is on, no one can touch it. If a prisoner comes in, and it's his first time, he turns the light on. (It starts in the off position.) After this prisoner turns it on, no one touches it until the leader comes. The leader always turns it off. Then, when someone else who has never gone goes, he turns the light back on until the leader comes again and turns it off. This goes on until the leader counts 99 times. Then he knows that everyone else has gone.

So leo was right but he had his offs and ons mixed up.

Okay. So they choose "23" to be the counter. 23 alone recognizes when everyone else has gone. That means that a consistent process must exist that means nothing to the others but everything to 23.

Person 1 walks in. The lightbulb is off. He leaves it off.
Person 2 through 99 leaves the lightbulb off.
23 sees the lightbulb off. He turns it on. That means that the counter has been there and has left a mark.

Now the counter has to know when 99 other people have been chosen.

Person 24 (or whatever number) walks in and sees the lightbulb on. He can't turn it off because it will reset....no it won't.

Everyone leaves the bulb off except 23. When he arrives, he turns it on. The next person, 47, remembers that the bulb was on when he arrived. He turns it off. It continues until 23 is chosen again. He turns the bulb on. The next person, 83, turns it off. 47 sees the bulb off and leaves it off, remembering that he has gone. If 47 is chosen after 23 again, he leaves the bulb on for the next person.

This continues until 23 walks in and sees the bulb on. Everyone ahead of him has left it on for the next person. He will be the last person and will announce that all 100 have been to the lightbulb. And he will be correct.

Wait, does that mean I have to pick a riddle? I'm no good at making them up. :/

Whoa, major ninjas. Leo is correct. So is MattEmAngel. Awesome logic!

CRAP. I solved it and was beaten. SERIOUSLY?!

No, you don't. Anyone can post a riddle, not just the person who got it right. And MattEmAngel got it right also.