Have you ever read the book “Get Us Out of Here!” by Maria Simma? Not approved by the church, but a vivid interview kind of book with the Souls from Purgatory communicating with her.
Dead people can't come back and communicate with the living.
What is appearing to people in the form of apparitions of dead relatives, etc, is demons.
Anyone who has visitations or apparitions is experiencing demonic activity.
Thanks, Salvation. I hadn’t read the book, but I did read about her here: http://www.mysticsofthechurch.com/2013/10/maria-simma-visits-from-souls-in.html I enjoyed the messages she [allegedly] had from the souls, starting off with, “That priests and nuns should always wear their habits/clerics, in as much as possible.”