The show was filmed entirely on the "Universal Studios" back lot in Hollywood. The town square is the same central place that was used in the "Back to the Future" trilogy. Subsequentially, Tom Wilson, who played Biff Tannen in the trilogy, has been known to pop up now and then in the show.
World-renowned psychic James Van Praagh served as a consultant during some episodes in the second season.
The stories are based in part on the work of spirit communicator Mary Ann Winkowski.
The pilot shows a California license plate on a vehicle. Subsequent license plates, which look like they're from New York, are generic.
Cesar Millan (also known as the "Dog Whisperer") featured a couple of times on this show. During season one, episode sixteen, "Dead Man's Ridge", the character Andrea was twice seen reading a book written by him. Then, in season two, episode eighteen, "Children of Ghosts", Cesar makes a cameo appearance as himself.