The psychical researchers W. W. Baggally and Everard Feilding exposed the British materialization medium Christopher Chambers as a fraud in 1905. A false moustache was discovered in the séance room which he used to fabricate the spirit materializations. The British medium Charles Eldred was exposed as a fraud in 1906. Eldred would sit in a chair in a curtained off area in the room known as a "séance cabinet". Various spirit figures would emerge from the cabinet and move around the séance room, however, it was discovered that the chair had a secret compartment that contained beards, cloths, masks, and wigs that Eldred would dress up in to fake the spirits.
In 1880 the American stage mentalist Washington Irving Bishop published a book revealing how mediums would use secret codes as the trick for their clairvoyant readings. The Seybert Commission was a group of faculty at the University of Pennsylvania who in 1884–1887 exposed fraudulent mediums such as Pierre L. O. A. Keeler and Henry Slade. The Fox sisters confessed to fraud in 1888. Margaret Fox revealed that she and her sister had produced the "spirit" rappings by cracking their toe joints.