spookist

plural spookists

1. informalA spiritualist or medium.

   The foolish, credulous dupes never for a moment consider the utter incongruousness of the association of their beloved dead or missing with these professional 'spookists.'

   2011, Stuart C. Cumberland, That Other World, page 18

   1 more example

   My father had a horror of girls' schools (and if he could “get through”—to use the orthodox expression of the spookists—he would find all his opinions on this subject more than justified by the manners, morals and learning of the young ladies of the present day) […]

   (Can we date this quote?), Margot Asquith, An Autobiography