Ghosts pass through solid wall/door. Celebrate finding a key. Unfortunately they cannot remove it from the room as it is solid and cannot pass through matter like they can. Ghosts get depressed about this.

You lift them from the bottom and there is a system of gears and springs (citation needed) that assist with them being raised and hold them in place.

Pull them down from the bottom and they come down (with some resistance).

I came looking for the Stargate joke. Did not leave disappointed.