It was an illustrated book of ghost stories. I took it out from the public library several times as a kid. I’m 32 now, but I distinctly remember two pictures from it. One was the ghost of a well-dressed man drifting across a vaulted ceiling, with bookshelves lining the walls on both sides. The other image is from a story which I think was called “The Nu.” The picture accompanying the story was pretty striking: the viewer was looking down a staircase illuminated by moonlight. A ghost covered completely by a white shroud, with a very tall white conical hat, was ascending the stairs. I know, this isn’t a lot of info. But it’s been a real pain to find, and I want to find it. Any help would be much appreciated!