Saw a great one a while ago that was supposedly on a Swedish chainsaw
CAUTION: Do not attempt to stop chainsaw with hands or genitals
I know I've seen one on a trash compactor that saws
ATTENTION: Crushing/Shearing hazard. do not climb inside.
I shudder to think that in order to think it necessary to put these labels on, someone had to have tried it.
I can here the conversations in my head now
"C'mon whats the worst that could happen? They call it morning wood."
"Hey I got's me an idea you hold my beer, I'm gonna climb inside this here stinky thingagummer, then you push the button and we'll see if I can get out before the walls crush me. It'll be like that there Indiana Jones, Or Star Wars or somethin..."