A few months ago I felt a strong desire to talk to my mother. This is not a problem, really, except that my mother has been dead for twenty years. So I talked to my therapist about it, and he led me through an empty-chair exercise.
This was not a séance, but it had some of the trappings of one. The therapist stood up, opened the office door, and beckoned my mother into the office. Once she was seated in the empty chair and the therapist had welcomed her into the room, he invited me to speak to her.