My dad rigged one up for me when i was in highschool
It was like a little electric motor with an offbalance weight on it, set to a timer.
I slept on a metal bunkbed, so when that thing went off, it basically made me jump out of bed
Honestly its a pretty disturbing way to wake up every morning, lol. But i guess it works
Atleast he never got to rigging up the hydrolic matress dumper that he talked about...