She "catches" him with a book on ghosts and wonders why he's interested? Ummmm, Carolyn dear, that is the most NORMAL thing we've seen in David.
When he asks if she's ever seen a ghost, she says "Why, have YOU?" Hello? You were there when Davey was making noises to anyone who would listen that all of his best friends were ghosts! C'mon, it hasn't been THAT long. For Davey's pals, Josette and little Sarah come to mind. I can't remember if he saw Bill Malloy or not, I know Vicky did. Any others since the beginning up to now? Other than Beth and Quentin, of course.