Someone else asked this question on another thread earlier, but it is such a striking question I believe it merits it's own post.
Why, indeed, do ghosts wear clothes? If there was any logic to the assumption that ghosts are departed spirits from people who have died, surely there wouldn't be clothes. Or would there? Has anyone on here seen a naked ghost?
Since we are referring to things spiritual appearing to those who are physical then choice of appearance is a very reasonable conjecture. The only things that are ridiculous in recent posts are the claim that such is ridiculous, and the attempt to steer a conversation to ridiculous extremes in order to mock. If that is all one has one ought not contribute to serious discussion.
In the same light as do they wear clothes question - why do they bother to come down stairs? If they can walk through walls why dont they fall through the floor?