The story of the Two Bad Mice.

In the summer of 2002, two Risleyites going by the aliases "Hunka Munka" and "Tom Thumb" were kicked out of their upstairs rooms because it was time to move out for the summer. However, these "two bad mice" had no other home. So they packed up their things, sneakreted a key from somewhere, and moved into the sewing shop.
The room was arranged so that all signs of life could be erased in a matter of minutes; ramen noodle packets were stored in the clear material bins with swatches of cloth wrapped around the outside, and so on.

This closet is where they slept.

However, the one thing the Mice weren't counting on was routine fire inspections. When one of the mice returned to "the den" one evening, she was shocked to find the room in disarray and the other mouse missing! Needless to say, she vacated in a hurry.

When she finally found her fellow mouse, weeks later (these mice had no phones, either... it's a very sad story), he told her that the fire inspectors had come in while he was sleeping and stomped around the room, checking everything while he clutched the blankets in fear.
Just as the inspectors were about to leave, they remembered to check the closet, and lo! a Ris-squatter. They called the police and the poor Rislophile was banned from campus for one whole year! (He didn't actually attend Cornell at the time... oops).

Luckily, this minor setback didn't prevent him from emceeing Rocky Horror a few months later.