Vox Media offers an easy-to-digest capsule of rational reasons why many people believe in (and sometimes believe that they’ve seen) ghosts, including a short interview with skeptical investigator Joe Nickell.
Like Mr. Nickell, Harry Houdini, Rose Mackenberg and numerous others over the past century-and-a-bit, I’ve found no persuasive evidence of ghosts; and, as much as anyone, I enjoy suspending disbelief to appreciate a good ghost story. It seems to me that the principle of suspension of disbelief might usefully be applied to any other aspect of the “supernatural”.