After burning a prop Ouji board, a series of catastrophic events plagued the production, including a blizzard, a fire (an actress' hair was singed) a flood, sets being destroyed, loss of funding, and loss of cast. The producers actually had two spiritual advisers come in to cleanse the bad mojo from the project.
Sharon says "Come into the light, children. All are welcome." This is a quote from Poltergeist (1982).
At about 4:00 minutes into the film, as Michelle is talking to her mom on the phone and packing her car, a green pickup truck is seen in the street. The driver of the truck flips off the camera.