School prank

I need idaes for a high school prank that cant be traced back to me.

And no sending hookers to a teachers house been there done that

 

You should build a digital clock inside of a small, metal case and show it to your science teacher. I hear people freak the fuck out over that.

 

In the questiin it says that i cant get traced back to it

 

You type good. Did you come up with any ideas yourself yet? It's been an entire month since you asked the question. Share what you've thought of on your own with us.