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."
2. Let the psychic guide the session. You’re paying a professional psychic for their time; allow them to do their job and lead the discussion where it needs to go. A good psychic should do most of the talking and asking you to validate or confirm the impressions they receive. You will likely frustrate an authentic psychic with your emotional overload by going off on tangents or venting your life story. And you’ll be giving a fraudulent psychic way too much information that can be manipulated to their advantage. When in doubt, politely ask the psychic if you may elaborate to underscore a point.
^ M. Lamar Keene. (1997). The Psychic Mafia. Prometheus Books. p 122. ISBN 978-1-57392-161-9 "A medium still riding high in England is Leslie Flint, famed as an exponent of direct voice. William Rauscher and Allen Spraggett, who attended a sitting Flint held in 1970 in New York, said that it was the most abysmal flop of any seance they had endured. All the spirit voices sounded exactly like the medium and displayed an incredible ignorance of nearly everything pertaining to the sitters. The "mediumship " was second-rate ventriloquism."
Many 19th century mediums were discovered to be engaged in fraud. While advocates of mediumship claim that their experiences are genuine, the Encyclopædia Britannica article on spiritualism notes in reference to a case in the 19th century that "...one by one, the Spiritualist mediums were discovered to be engaged in fraud, sometimes employing the techniques of stage magicians in their attempts to convince people of their clairvoyant powers." The article also notes that "the exposure of widespread fraud within the spiritualist movement severely damaged its reputation and pushed it to the fringes of society in the United States."