Remember that relatively moderate religious denomination that more Americans belong to than any other faith (in excess of sixty million)? It is called Roman Catholicism. Oh yeah, and it still offers its priests courses in how to conduct exorcisms. If a person near you is demon infested, an alumni of this course will know what to do. Of course, if you actually believe that someone near you is demon infested, in all likelihood, the person with problems is you.
Hat tip to Secular Front.