Gracey Manor is modeled after the original Disneyland Haunted Mansion. Crump Manor is modeled after Magic Kingdom's Haunted Mansion at Walt Disney World.
The namesake of "William Gracey" and the "Gracey Manor" (the Haunted Mansion's mansion name), stems from Yale Gracey, a Disney Imagineer and member of the Academy of Magical Arts (their clubhouse is The Magic Castle in Hollywood, CA). Yale was the one who created a modernized version of "Pepper's Ghost Illusion." He showed a model to Walt Disney, who loved it and honored Yale by calling the mansion "The Gracey Mansion." The attraction still holds the largest display of Pepper's Ghost Illusion in the world (it is the dining room scene with the ghosts flying around the table). The original, working, model is still on display at The Magic Castle in Hollywood, California.
The chair in which Harriet is seated at the spirit session, and in which she is later expelled from the Mansion, resembles the ride vehicles, known as "Doombuggies", in the Haunted Mansion ride in the Disney parks.
Eddie Murphy, star of The Haunted Mansion (2003), was invited back to make a cameo appearance but was turned down when he demanded $500,000 for one days work.
Vic, the cohost at Crump Manor, can be briefly heard to play the theme to another Disney attraction, "it's a Small World," on the piano.
Winona Ryder: Uncredited, as Pat, a tour guide. Ryder starred in the similar film Beetlejuice (1988).
Dan Levy: As Vic, a tour guide. Levy is billed seventh but has less than 30 seconds of screen time in the finished film.