“Haints” are pretty common among the Protestants around where I live, particularly among the charismatic populations (Holiness and Pentecostals). I’ve never heard of it being thought of as a Catholic thing.
Supernatural occurrences are considered fairly normal among most pagans and in heathenry, I don’t know too many people who don’t have a story of some sort, although I think in some cases it becomes a “Oh, yeah, I’ve seen a ghost, too” thing for some more impressionable types. In heathenry, we have the tradition of our ancestors keeping an eye on us as well as the “hidden people”, so we don’t tend to pay them a whole lot of mind aside from leaving them offerings unless they’re troublesome.
It does worry me a little, though, as someone who is considering becoming Catholic, how I would have to rethink this within a Christian context.