In old-line Spiritualism, a portion of the services, generally toward the end, is given over to demonstrations of mediumship through contact with the spirits of the dead. A typical example of this way of describing a mediumistic church service is found in the 1958 autobiography of C. Dorreen Phillips. She writes of the worship services at the Spiritualist Camp Chesterfield in Chesterfield, Indiana: "Services are held each afternoon, consisting of hymns, a lecture on philosophy, and demonstrations of mediumship."[20]
The medium Henry Slade was caught in fraud many times throughout his career. In a séance in 1876 in London Ray Lankester and Bryan Donkin snatched his slate before the "spirit" message was supposed to be written, and found the writing already there.[78] Slade also played an accordion with one hand under the table and claimed spirits would play it. The magician Chung Ling Soo revealed how Slade had performed the trick.[79]
In 1918, Joseph Jastrow wrote about the tricks of Eusapia Palladino who was an expert at freeing her hands and feet from the control in the séance room.[121] In the séance room Palladino would move curtains from a distance by releasing a jet of air from a rubber bulb that she had in her hand.[122] According to the psychical researcher Harry Price "Her tricks were usually childish: long hairs attached to small objects in order to produce 'telekinetic movements'; the gradual substitution of one hand for two when being controlled by sitters; the production of 'phenomena' with a foot which had been surreptitiously removed from its shoe and so on."[123]

Senses used by mental mediums are sometimes defined differently from in other paranormal fields. A medium is said to have psychic abilities but not all psychics function as mediums. The term clairvoyance, for instance, may include seeing spirit and visions instilled by the spirit world. The Parapsychological Association defines "clairvoyance" as information derived directly from an external physical source.[37]