First of all, DON'T PANIC! Second of all, DON'T CONTACT THE CATLICK CHURCH! Demon infestations, while absolutely horrible, are fairly common and can be dealt with easily by True Christians™, so as long as you contact a pastor and set up a generous tithing program you should be fine. You definitely should NOT contact a catlick exorcist though, because they aren't true believers and usually make problems with demons worse.
Our neighbor always says to just use a shotgun then we don't have to worry about anything but then again old Mr. Lester is a not a True Christian™. My dad always suggests to just run them over with the Ford and then again our Uncle suggests doing it old-school by burning them by the stake.
I have a question though, would a demon be encouraged to stay in a young choir boy if you contacted a Cathlick priest? Would the demon enjoy the molestation or would he leave the body?