The Tale of the Dream Girl - S3-E10
Trivia: It's widely speculated that this episode inspired the movie "The Sixth Sense," although the movie's director, M. Night Shyamalan, claims that he has never watched it.
Trivia: The series was cancelled before the kids were able to learn who Ghostwriter was in his previous life. Producer Kermit Frazier revealed in 2010 that Ghostwriter was a runaway slave during the Civil War who was hunted down and killed while teaching other runaway slaves to read in the woods, and that his soul became trapped in the book that he emerged from Jamal's basement.