Please use other door
I'm always looking for crazy signs and other user interface type things which don't make sense. Sometimes, this is far too easy. Here's one I encountered in Google's building 46 back in 2007:
Okay, no big deal, right? Use the other door.
Right, so, click on the image to see the full scene and see what your reaction is. (I couldn't make it fit here while still being legible.)
There were no other doors in the immediate surroundings. You'd have to go back around through some other offices to reach the lobby which was behind those signs.
At least we didn't have a fire.