^ Leonard Zusne, Warren H. Jones. (1989). Anomalistic Psychology: A Study of Magical Thinking. Psychology Press. p. 221. ISBN 978-0-8058-0508-6 "The spirits, controls, and guides of a medium are the products of the medium's own psychological dynamics. On the one hand, they personify the medium's hidden impulses and wish life. On the other, they are also shaped by the expectations of the medium's sitters, the medium's experience, the cultural background, and the spirit of the times."
Today "demonstration of mediumship" is part of the church service at all churches affiliated with the National Spiritualist Association of Churches (NSAC) and the Spiritualists' National Union (SNU). Demonstration links to NSAC's Declaration of Principal #9. "We affirm that the precepts of Prophecy and Healing are Divine attributes proven through Mediumship."
Just as in any profession, mediums have specialties and areas of expertise. Unlike Allison Dubois in Medium, I don't work with the police in solving crimes. Or, unlike Melinda Gordon in The Ghost Whisperer, I don't help tormented souls cross over. Over the years, it has become very clear that my job lies in working with souls who have happily crossed over to the other side and, for the most part, are at peace. Sure, they may have regrets or unresolved issues, but they're not haunted or lost. Oftentimes, it's the living that are not at peace. The main goal of your deceased loved ones and spirit guides is to assist you in moving on, free of grief and struggle, so you can fulfill your life lessons and enjoy your time here on earth.
In September 1878 the British medium Charles Williams and his fellow-medium at the time, A. Rita, were detected in trickery at Amsterdam. During the séance a materialized spirit was seized and found to be Rita and a bottle of phosphorus oil, muslin and a false beard were found amongst the two mediums. In 1882 C. E. Wood was exposed in a séance in Peterborough. Her Indian spirit control "Pocka" was found to be the medium on her knees, covered in muslin.