This is a very good question. I am Hindu , we have a great deal of daemons too. But we don't mix up with religion or god. We have a priest or other professionals deal with it in a similar fashion. We also use holy water and enchant sanskrit phrases. But we dont have the concept of satan. So we believe weaker mind gets posessed easily or the devil wants to haunt intentionally for the crime commited when it was alive. I think the Abramic religion categorizes every thing into good and bad. It makes it easier for them to explain some one is possessed because of their sins or belief in Satan.I think ,In general daemons are failed soul who couldn't transform to the next level after death.
To the OP: Why do you think that non-Catholics aren't getting possessed? There are several instances in both ancient and modern times, of non-Catholics getting possessed including in places like Japan for example. It's just that possessions involving Catholics seem to be the most common in western nations and thus the most popular.