Don't Be Afraid, I'm a Ghost

Do you believe there are ghosts in this world? Have you or anyone around you seen it? Or are you a ghost? Are there ghosts around you? Do you really understand? How can you be sure that you or the people around you are not? When you are walking alone at night, have you ever felt that there is someone behind you? When you are alone in a room, are you really alone? Are you really you? ? ?