Origin of the phrase "A wild hair up his a**"

Factual Questions
1

First off, is it wild HAIR or wild HARE? And where on earth did this saying come from?

2

It’s only “hare” if you’re Richard Gere attempting a more broadening experience, so to speak.

3

It’s wild hair.

It seems to have come into use about the early 1950’s in print. My guess is started being used in WWII.