According to James Randi, a skeptic who has debunked many claims of psychic ability and uncovered fraudulent practices, mediums who do cold readings "fish, suggest possibilities, make educated guesses and give options." Randi has a standing offer of $1 million US dollars for anyone who can demonstrate psychic ability under controlled conditions. Most prominent psychics and mediums have not taken up his offer.
The British medium William Roy earned over £50,000 from his séance sitters. He confessed to fraud in 1958 revealing the microphone and trick-apparatus that he had used. The automatic writings of the Irish medium Geraldine Cummins were analyzed by psychical researchers in the 1960s and they revealed that she worked as a cataloguer at the National Library of Ireland and took information from various books that would appear in her automatic writings about ancient history. https://drive.google.com/file/d/1j9OXTL0I-NYzWv7GGPZjWvnWCNACHJFh/view?usp=sharing
^ 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."
In the late 1920s and early 1930s there were around one quarter of a million practising Spiritualists and some two thousand Spiritualist societies in the UK in addition to flourishing microcultures of platform mediumship and 'home circles'. Spiritualism continues to be practised, primarily through various denominational Spiritualist churches in the United States, Canada, Australia and the United Kingdom. In the United Kingdom, over 340 Spiritualist churches and centres open their doors to the public and free demonstrations of mediumship are regularly performed.