The story of your nephew is very creepy. Hospitals are known to have a lot of negative energy that invites astral beings to stay in the hospital. Why is that? Because the hospital is the place where all accidents are helped, some people survive and some people die while being treated. I once stayed at a hospital looking after my father who was being treated. I could feel the air of the hospital at night was very different from the daytime. At night it feels very cold, quiet, and occasionally I get goosebumps. I don't know why that is? Maybe the negative energy is very strong there.