This is from 1969:
https://www.youtube.com/watch?v=_kQcuhoZD0Y

I wouldn't be surprised if the original joke goes back to the silent movie era.

i kind of hate this because the keys are not incorporeal. So while the ghost can go through the door with ease the keys can't even if the ghost could interact with the keys in the first place. 😜

Funny story, possibly apocryphal since it's a friend of a friend kind of deal. Anyway, one person in a household gets up early every morning for work and wants to lock the door so that people inside are safe, but also so that they have the key. The lock wasn't the sort that automatically locks when someone leaves.

Their usual routine was to lock the door then post the key back through the letter slot in the door.

One day, this person's neighbour finds them trying and failing to reach in through the letter slot in the door in order to get the key back.

"Why are you doing that? What's wrong?"

"I've forgotten to lock the door before putting the key back through. Can you get me something like a coat hanger or something so I can reach it?"

"So, it's not locked?"

"No! And it needs to be!"

"Why can't you just open it?"

"I don't have the key!"

The neighbour had to grab the handle and open the door to resolve the confusion.

Some argue that the keys should not be able to pass through the door, even with ghost interaction. I argue that my keys can metaphysicaly appear and dissappear, also behind closed doors. So those are apparently my keys! 🔑🗝

Ghosts can't go through doors, stupid. They're not fire!