"Bill" wrote in message
stuff snipped

Ok, this is way weird. I just was going to replace a toilet flapper. I
went to turn the shut off valve, and got zapped, big time!

It's not that weird. As has been pointed out, some malfunctioning
appliance is grounded to your plumbing. As has been suggested, get a
professional to isolate the problem before someone gets hurt!

Congratulations! Yours is the second right answer (get a professional) had
this been an actual situation with human life at risk instead of dumb-ass
troll attack. If we don't know anything about the OP's skill level, with
electrical work it's better to underestimate it.

--
Bobby G.