No, it’s you who doesn’t understand Familiar Spirits. If a witch has a “Familiar spirit”, the spirit speaks through the witch. If you think an apparition of Samuel was in the room, wouldn’t Saul have hugged it or shook his hand? Weeped on his shoulder?
What part of “Samuel said to Saul” are you not understanding? You are letting your preconceived notions interpret the plain meaning of the text.