I've had a few experiences that could not be otherwise explained that I would label 'creepy'.
One of which was several years ago when I was working night shift at the Shelter.
I was walking through the old house and clearly heard a female voice behind me when I knew all of the clients were in their rooms for the evening and all TVs and Radios were off and you could not routinely hear noises from the street.
Another time in the same old building, one of the clients came into the office and asked who the man was they had just seen in the hallway on the first floor. At the time, I was the only man in the building and the side entrance was locked.
Yeah, there were times when that could be an interesting place to work.
I've seen plenty of 'orbs' even got a few pictures of them, but I wouldn't call them 'creepy'. One was posted on the theater photoessay on The Media Desk website.
I've also seen shadows that move more or less intelligently and occasionally in opposition to the movement, or lack thereof, of light sources. Interesting? yes. Creepy? maybe not.
As for other manifestations from "the other side" or "beyond" or whatever, most of them can be understood, and what can be understood, should not be faced with an irrational level of fear. OR, just as dangerous, an intense level of curiosity.
Some things ARE just better off being left alone.