A visit from a long lost friend

About three years ago a sound had woke me up. At first I thought it was my son getting up and I ignored it. Unfortunately the sound persisted right outside my bedroom door.
When I turned to get out of bed I saw a man cross the bedroom door. I instantly thought that I had been dreaming since I recognized the man as someone I had known years before.
Of course I got up and found that nothing and no one was there. In the course of a few days I had forgotten my visitor.
Weeks later I was talking with an acquaintance of mine and had found out that the gentleman I had known passed away on the very night I had seen him cross my bedroom door.

One night I had awoken from the feeling of being watched. When I woke up I saw a dark figure standing at my bedroom door. I blinked several times and the figure was still there, I had even pinched myself to make sure I was awake. A few minutes later the figure vanished and so did my will to sleep. This was the first appearance.
Within a few days I had found out that my mother had to have open heart surgery. We all were anxious and the day of surgery came. My mother came through the surgery ok.
The night after her surgery I had be awakened yet again to the feeling that I was being watched and found, once again, the figure at the door looking in on me. I found out that one of mother's blood vessels had exploded and she had almost bled to death.
Mom went home and life went back to normal.
A few months later I again woke up and found "my friend" standing at the door staring at me. Later that morning I received a call from my sister telling me that Mom was back in the hospital, this time with pneumonia. She was admitted at the exact time the figure appeared at my door.
There have been other times that this "man" has appeared and every time he has my mother has been in need of medical help.
I have learned since then that every time I see this figure standing at my door to call my Mom at once