How to lose your fright for ghosts?

OK! So I'm a 13 year old guy, and sometimes I'm afraid of dead persons who's invisible and are walking around and making fun of me and scaring me. AKA Ghosts. I'm a christian, so I know they don't exist. It's just psychically in my head. I don't want any bull$HIT answers like: Sing I'm not afraid of gooohsts ten times. HELP MEEE!!