Saul’s Demon

With whom did King Saul and the witch of Endor communicate? Was it indeed the dead prophet Samuel, as some commentaries claim, who told Saul about the future, even though God had refused to talk to him through prophets? Or are other commentaries correct, which state that it was a demon who pretended to be Samuel? Could Saul’s prior experiences with a demon be significant? What does God tell us about demons and those who want to consult the dead?