(On a much smaller scale) - I had a plasma ball toy as a kid, the kind you put your finger on and the electricity arcs to your finger. One day I broke the glass housing. Curious what would happen, I plugged it in - the radio in the kitchen AND the TV in the living room both simultaneously wouldn't run when the broken plasma bulb was plugged in. I did this several times as a prank on unsuspecting family members and then the unit burned out/wouldn't turn on. I still don't know how dangerous this was to do(if at all).