The title of the episode is a reference to the 1963 film, The Haunting, as well as the 1981 werewolf film, The Howling.
The idea of an ominous phrase which only makes sense when viewed in a mirror is a reference to The Shining where Danny writes "redrum", and when seen in the mirror spells "murder." The number which Bender sees, 1010011010, is the binary value for 666.
The painting with the moving eyes is of a robot named Commodore LXIV. Commodore 64 is a popular early home computer.
The will reading scene is a tribute to a 1971 (approx.) Volkswagon Beetle TV ad showing a long funeral procession of relatives. All of whom the wealthy deceased gentleman deemed to be unworthy of receiving anything from his estate; with the exception of his nephew who examplified his thriftiness by buying a Beetle. To which the deceased declares in the closing voice over, "And finally to my nephew...to whom I leave my entire estate of $10,000,000".
The scary theme in the castle is actually the default boot-up sound of Windows 98.
Fry's comment, "Hey Project Satan, over here! I'm a blind pedestrian! 20 points!" refers to a cult-film from the 1970's, Death Race 2000.
The scene in which Bender is within the living room of the castle; seated with his knees positioned upright and teeth chattering is in reference to the 1942 animated short "Jasper and the Haunted House"