I don't like to post a lot of things that people already know but I think lots of folks think there is no easy solution for a ghost swing door. If you have a door that doesn't want to stay open or closed and swings like a ghost is handling it, there is an easy free fix.
This short video shows how to fix a door so it won't ghost swing. Basically, you remove the top hinge pin and tap the pin to create a slight bow in the pin (such that it is not perfectly straight). The bow in the pin creates friction when seated in the hinge and allows the door to stay in place.