From its earliest beginnings to contemporary times, mediumship practices have had many instances of fraud and trickery. Séances take place in darkness so the poor lighting conditions can become an easy opportunity for fraud. Physical mediumship that has been investigated by scientists has been discovered to be the result of deception and trickery. Ectoplasm, a supposed paranormal substance, was revealed to have been made from cheesecloth, butter, muslin, and cloth. Mediums would also stick cut-out faces from magazines and newspapers onto cloth or on other props and use plastic dolls in their séances to pretend to their audiences spirits were contacting them. Lewis Spence in his book An Encyclopaedia of Occultism (1960) wrote:
From time to time, it may be helpful to seek out the counsel of someone objective for guidance or connection with spirit, and/or to gain a clearer read on your life. If a psychic, medium or any other intuitive healer speaks to you, I encourage you to set your intentions and then simply let go and go with the flow. Spirit will guide you as to who and what is in your highest and best good in that moment. Also, please remember that no one knows you better than yourself, and no one has a closer connection with your deceased loved ones and spiritual guides than you do. By learning to go within, listen to and trust your own inner voice, you gain access to everything you'll ever need to know. And what could be better than that?
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.