It does not appear when Saul had suppressed witchcraft; it was probably in the early part of his reign.
Familiar spirits ... wizards - i. e. ventriloquists ... wise or cunning men. See Leviticus 19:31 note.
Related Commentaries of 1 Samuel 28:3
1 Samuel 28:3
3 Now Samuel was dead, and all Israel had lamented him, and buried him in Ramah, even in his own city. And Saul had put away those that had familiar spirits, and the wizards, out of the land.