Am I going to die if I touch it again?
Well not likely but the computer could go up in a puff soon...I would check that your outlet is properly grounded, you are using the proper 3 wire power cord, the ground pin isn't ripped off and there isn't any bare wires inside the case. Also check for the M.B. shorting against the case.
If all this checks out then I would suspect the Power Supply and rather than risking disassembly, pick up a replacement.