During his speech about the Dagmar family, Dave (Monte Markham) notes that the home's first owner sold corpses to the "University over in Essex County" - a reference to author H.P. Lovecraft's fictional Miskatonic University, which was located there.
Numerous characters in this film are named after characters or people associated with the Lucio Fulci film The House by the Cemetery (1981), which this film was inspired by.
During the credits, around 1:20:00, there is a bonus scene.
The burn make-up on the Dagmar family ghosts took about two hours to apply and one hour to remove.