I understand that there are usually more ghosts in hospitals
than elsewhere because those things like bloody places. Hospitals
are full of patients who are ill so the human chi is lesser.
It's true that hospitals generally don't have good energy (qi/chi),
as there are many deaths, and often patients don't die peacefully
when they are in great pain from their illnesses. The state of
mind of such patients in great suffering at the point of death is
hard to be positive. The result is that they have a higher chance
of not successfully crossing over to the Light (spiritual realm),
and end up as ghosts at the hospital.
That's the reason it is not advisable to stay too near a
hospital, for people who are vulnerable to the effects of negative
energy.
Rainbow Jigsaw of Life