Sciomancy
SCIOMANCY (Gr. OKI&, shade, shadow, and navreta, soothsaying, divination), a form of divination by means of supposed communication with the shades or spirits of the dead. The calling up of the spirit of Samuel by the Witch at Endor when consulted by Saul is the classical example (i Sam. xxviii.).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)