[raccoonnookkeeper]

Touch White, you'll be alright.
Touch Black, it'll set you back.

Or think "to be burned black." Some old wiring jobs are so faded that it's almost impossible to tell what the white and black wires are.

And technically, even if wiring was all done properly to code, you can STILL get knocked on your can by touching a separated white (and a ground). It might be carrying the return from a circuit that's live with something plugged in that always carries current.

[Paladin2]

I made the same discovery simultaneously with the white/ black thing. Just because the switch is off doesn't mean that the things it operates aren't hot.

Lots of electronics is run by "connecting" the ground. Turns out that house electricians like to do the same thing.