One of the foremost men of God in recorded human history -- whose word never fell to the ground, never failed, was never rendered inoperative or obsolete -- cannot have turned against his God, his Savior and Lord beyond the grave. It is inconceivable that Samuel would defy his Father, his Master, his Beloved at the summons of a witch! And Saul, who was rejected for repeatedly rejecting the Word of IEUE, suffered the consequences for his disobedience. For fraternizing with demons, he was entangled in the curse of death they pronounced against him.
The Word of IEUE which Saul in his end defied:
9 When thou art come into the land which the LORD thy God giveth thee, thou shalt not learn to do after the abominations of those nations.
10 There shall not be found among you any one that maketh his son or his daughter to pass through the fire, or that useth divination, or an observer of times, or an enchanter (who uses spell inducing potions, drugs), or a witch,
11 Or a charmer (a hypnotist), or a consulter with familiar spirits, or a wizard, or a necromancer (a medium who contacts the dead).
12 For all that do these things are an abomination unto the LORD: and because of these abominations the LORD thy God doth drive them out from before thee.
13 Thou shalt be perfect with the LORD thy God.
14 For these nations, which thou shalt possess, hearkened unto observers of times, and unto diviners: but as for thee, the LORD thy God hath not suffered thee so to do.
--- Deuteronomy 18:9-14, AV