1 Samuel 28:7 KJV
Then said Saul unto his servants, Seek me a woman that hath a familiar spirit, that I may go to her, and enquire of her. And his servants said to him, Behold, there is a woman that hath a familiar spirit at Endor.
1 Samuel 28:8 KJV
And Saul disguised himself, and put on other raiment, and he went, and two men with him, and they came to the woman by night: and he said, I pray thee, divine unto me by the familiar spirit, and bring me him up, whom I shall name unto thee.
A few remarks:
1. The woman had a familiar spirit, that is, a demon.
2. The communication with Samuel was to take place via the demon. Saul would ask, the woman has her visions or whatever, then she reports back to Saul. Everything is happening in the witch's trance state and is being reported by her to Saul.
3.
Does it not seem strange that a possessed witch has the power to raise the dead?
My conclusion: Samuel was dead and stayed dead, the woman had a demon, and the events are part of Saul's downfall.
See also:
1 Kings 22:19-23 KJV
And he said, Hear thou therefore the word of the Lord : I saw the Lord sitting on his throne, and all the host of heaven standing by him on his right hand and on his left. [20] And the Lord said, Who shall persuade Ahab, that he may go up and fall at Ramoth-gilead? And one said on this manner, and another said on that manner. [21] And there came forth a spirit, and stood before the Lord, and said, I will persuade him. [22] And the Lord said unto him, Wherewith? And he said, I will go forth, and I will be a lying spirit in the mouth of all his prophets. And he said, Thou shalt persuade him, and prevail also: go forth, and do so. [23] Now therefore, behold, the Lord hath put a lying spirit in the mouth of all these thy prophets, and the Lord hath spoken evil concerning thee.