Do you use "haunt" as a noun? You will after seeing The American Scream, playing this weekend at Nitehawk. The documentary follows three families in Fairhaven, Massachusetts, as they turn their homes and yards into elaborate haunted houses for Halloween. While the movie touches lightly on the thriving subculture of "home haunts," its real focus is on the significance of these haunted houses for the people building them --- one a perfectionist with professional haunting ambitions who is making up for a childhood deprived of Halloween, another a recent convert who sees it mostly as an amusing pastime, and a third a social misfit who uses it as a way of bonding with his father. More fascinating than frightening, it's a window into a world with dark and mysterious corners.