This post reminds me of my days as a Dungeon Master. I would always put a button or lever of some type in the adventures I designed. They were ALWAYS a trap.
Invariably this discussion would ensue:
Me: You enter the room. It is roughly 20 by 20 feet square with a slightly acrid smell. The walls are decorated with elaborate gargoyle faces carved into the very stone. Aside from a large lever near a grate in the center of the floor, the room is otherwise empty.
Player one: Okay let's leave, this is obviously a trap.
Player two: We're not going to pull the lever?
Player one: No, levers are always a trap and this one is obviously a trap. Look at those gargoyles.
Player two: What about them?
Player one: Their mouths are open. If you pull that lever, something bad will come out.
Player two: Maybe it will be something good this time?
Player one: Do you remember the last time, when Sir Thomas died? Or the time before that when we lost Fezzik and Draconis?
Player two: Every lever in the realm can't be a trap. Some of them have to be for something good. Why would they make levers if they only made bad stuff happen?
Player one: I'm telling you if we pull this lever, something bad will happen.
Me: With a loud thud, a huge stone drops in front of the only door. A clear liquid begins to trickle from the mouths of the gargoyles.
Player one: What the hell?
Player three: Sorry guys, I couldn't resist the lever. I had to pull it.
Me: The trickle of fluid surges into a gush. As the liquid begins to cover the floor, you notice that boots are beginning to smoke.
Player one: Dammit, I told you this was a trap!
Good times, good times. Welcome to the forum.