Weird Washroom Experiences

My present workplace is situated on the bank of the Demerara River. There are no known instances of ghosts or supernatural beings sightings that was ever mentioned to me nor did I ask anyone if they had ever experienced any sort of paranormal presence in the building.

I usually work late and quite often I'm the last to leave the building so naturally I tend to get a bit nervy and on edge after everyone is gone. I used to work in the bottom flat of the building but now I'm on the top flat near the washroom in question.

A few times I felt "something" and when I look in the direction of this something I would catch a glimpse of a shadow moving towards the washroom.

One time while doing my thing, it sounded and felt like a flock of birds descended on me when I looked up nothing was there. I also felt like air was gushing through an open crack blowing on the left side of my rib cage but there was no opening anywhere. This happened about 2:00 pm, while most people were at work.

Sometimes I would hear sounds like someone was listening to a radio but due to the location of the building, that someone would have had to be in the building just below the washroom. However, that room is just an empty store room.

Sometimes water would be flowing at the kitchen adjoining the washroom, when I look at the sink, it would stop then when I leave I would hear it running again. Sometimes I hear the water running in the pipes and when I turn on the tap - no water.

I'm not sure if these experiences can be counted among those "closer" encounters that I've seen in some stories but I would like someone to help me rationally explain some of these instances. Perhaps I missed something that was obvious...