This is a very simple way to set up a booby trap inside your house for your friends and family, It can get messy so prank at your own risk.
You will need the following household items.
2 Push pins
Basically you fill up the balloon with shaving cream to a desired size, You tape that balloon on top of any door. On the wall directly in front of the balloon attach the push pins which you will join together. Now you can get an idea of what will happen next.