I've worked more than a couple of decades in Healthcare. A couple of places were old when I worked there- a lot of history and a lot of deaths/depressing incidents occurred in those walls.
I'll focus in this email on the small rural hospital. I was 18 at the time working mostly day shift, but would occasionally come in early to help night shift. On this one particular day, I had come in a couple of hours early to help. There was a patient in an isolation room, which was set back off the main hallway a few feet. I was handing clean linen into the room and standing in the little offshoot hallway. I distinctly heard foot steps coming down the main hall toward the isolation hall. Being night shift, there weren't many people on the floor. In fact, other than the 2 co workers in the iso room, there was only a nurse present. Now, there was an elderly lady who had been on the unit for a long time- she would always tell us to tell the kids in the hallway to slow down and to quit running. We always assumed this was a throwback to her career working with kids. But on this night, as I ducked my head back into the hallway to be ready to assist my coworkers, I'll be damned if I didn't hear several sets of footsteps break into a run coming down the main hallway toward my position. When I looked there was no one there, of course, and I could see the nurse charting in the nurses station. And, unless the nurse was supersonic and able to make herself sound like several people at once, it wasn't her making the noise. The ladies later told me that everyone else that had been there a while had heard them, so they welcomed me to their club.
There were also a lot of longer term patients on that unit. There was one section in particular where people would swear they heard music, usually 1940s tunes. Usually once they said they heard this, they usually didn't have much longer to live. Also in this section, there were times that the elevator would open up randomly, usually again, when someone was about to pass.
The last major incident involved a person who was what could be termed as a frequent flier to the hospital. We loved this man, but it was obvious he could no longer care for himself anymore. I was walking by his room on what would be his last hospital stay, and I had to do a double take. At the end of his bed I saw a female with a longer skirt standing and watching him. A co worker saw my weird reaction when I stopped suddenly to do my double take. She asked what was wrong, and I hesitated before telling her that I swear I saw a woman watching the patient sleep, but obviously no one was there. She asked me to describe the lady, and when I did she looked at me funny. She had been a lifelong resident of this small town and knew many people, and she stated that I had described his now dead wife to a "T". We guessed (correctly) that he may not be long for the world and his wife was looking over him.
I also worked in an old nursing home and had a few experiences there too, but I'll leave that for another time.