I'm really not sure what to say here, other than maybe it's a regional thing as I know for a fact that it's a common practice for local Pastors to visit the sick and shut-ins to pray over them and basically just see to their spiritual needs. One other thing which may make identifying these Pastors a little more difficult is that they don't usually wear any special vestments or other signs of their office. Most just wear their normal street clothes.
All pastors check in at the nurse’s station. None that I know of have ever visited the locked psych wards.