I do not believe that God lets people, souls, ghosts walk the earth. I do not believe he lets them have contact with us on earth. Now with that said, I believe any activity of this sort is real, and is evil, from the evil one . They are demons. Yes I have witnessed demonic activity where I work. Most who worked there called them ghosts, I call it demons. Through it all I believed these demons exposed themselves to get that response. To get people to believe they were souls walking the earth. I saw it for what it was and kept my faith and believe in God.