Why Is My Desktop Computer Grounded?

Hi guys,
I noticed this one problem lately about my computer. Whenever I make contact with my Desktop Computer, a receive a mild to strong jolt of electricity which causes me to freak out sometimes. Is this normal to all Desktop Computers or is there some sort of hardware troubling shooting I need to do to fix this problem?
I appreciate and welcome all advice that you guys can share about my computer problem. Thank you and good day.
Leon
