Ghost Elevator Prank from Brazil Goes Viral on Youtube [VIDEO]

This video has blown up world wide! If you haven't seen this, you need to check this out. It is a simple, yet complex prank if that makes any sense at all. People get in an elevator and the lights flicker, the power goes out and... well... check out the reactions of the people when they find out they are not alone.

How would you react if you thought that someone kept appearing and disappearing?What is your scariest elevator experience?