Don't Knock
I worked at a provincial hospital in the Philippines back in the year 2011. A lot of inexplicable things happened to me in that place, and this was one of the first ones.
The store room in our ward where we kept our medical stocks and spare oxygen tanks didn't have a lock. One night while I was on a graveyard shift, I needed to get a tank ready for one of my patients so I tried to push the door open, only to find out that I couldn't!
"Strange," I thought, because throughout the day nurses would just go in and out of that room without any hassle. I tried to push harder, thinking that some boxes or stocks may have just fallen on the floor and was now blocking the door. I didn't have anyone else in the station to help me because the nurse that I was working with was on her break at the time.
Annoyed and without really putting much thought into it, I knocked on the door and said quietly, "Please let me in, my patient will soon need this." Before giving up, I decided to try and push the door one last time. The next thing I knew, I had almost toppled into the dark, little room, which I could swear was a number of degrees much cooler than usual.
The door had swung open. Nothing was blocking the door, and everything was in order.
And I swear, in the few moments I spent in that eerily quiet room before rushing out in fear... I felt that someone was standing in there with me, breathing heavily, staring...