What is that word?

There must be a word in the English language for phrases you read that can have double meanings. It's kind of funny how my mind works because I often find myself amused by the signs I read in different places that can mean something completely different than what was intended. Take, for example, the sign I saw recently at a water park.

"Severe Weather Shut Off Button"

This sign made me think to myself... how ingenious is that? If the water park is full of people and severe weather approaches, all an alert employee needs to do is run over and depress this button... and off goes the severe weather. Think about how many potential applications there are for such a button in parks, sports arenas, golf courses... virtually any outdoor gathering place. I hope the person who invented that button got a patent for it and is living a comfortable retirement in a place so serene as to not require their invention.