I can personally attest to the complete inadvisability of touching a Radio Shack microphone with your lips, while holding the metal mic stand, barefoot, on a cement floor. I may have touched the base of the stand with my toe, too.
It left a pea sized purple lump on my lip that didn’t go away for quite some time.
My ex got such a zap from a faulty guitar that it knocked him right on his rear, onstage at a gig. Now that’s embarrassing!