This is not my story, but I will tell it as it was told to me with names changed.
A friend of mine once worked in a cardiothoracic unit in a large city. One night shift they were looking after the usual sick patients and expecting Mrs. Smith to die that night - family were called and everyone prepared. Another patient had overheard and stated to them "Mrs Smith is not going to die tonight but Mr. Jones over there is". "No, no" they said, "He is fine, it Mrs. Smith who is dying". the patient then said "No, Mr. Jones will die tonight as I can see all his relatives around him waiting for him". This is taking place after visiting time and the ward was empty except for staff and patients. Later that night Mr. Jones died unexpectedly and Mrs. Smith survived the night.
I tell this story because Jobbing doctor has something similar on his site here and every nurse has heard stories about green ladies, grey ladies etc. When I do nightshift in one part of the hospital, I am convinced I can hear a baby crying although there is no way that a baby can be in that area - other nurses have heard it too. Although I have wandered all over our old hospital on nightshift I have neither seen or heard anything out of the ordinary. One of my friends, a big rough tough guy is absolutely convinced that our old department is haunted. I leave it to the reader to give any explanations or reasons.