About a year ago, my mother rented a run down duplex. It was a complete eyesore but we were on a budget. My parents are divorced and, at the time, I spent every weekend with my mother.
This place always gave me a bad feeling in the pit of my stomach. At all times in this house, I felt like I was being watched. It didn't really matter if the room was full of people, this feeling never left me. Since I was only there on the weekends, though, I didn't know about most of the weird things happening until after mom moved out. Her roommate (and later, boyfriend), Vince, was also present for these happenings.
My mother is a firm believer in the craft, and always kept candles and incense burning in her bedroom for protection. I always stayed in her room at night, and she slept on the couch or in Vince's room. The one experience I do remember having with this entity was when I was in bed watching "Roseanne" after everyone else had gone to sleep.
I remember looking up and seeing a dense shadow of a man in the doorway, as if he was barred from the room. At first I thought it was the trick of the light but no matter how many times I rubbed my eyes or blinked, it stayed, staring at me until it finally turned and stomped down the hallway like it was angry. But I couldn't hear its footsteps; only see the way it moved.
About a week after Mom got her new apartment (she was still in the process of getting her stuff out of the house), we where in the kitchen of her new apartment, playing a game of cards. We were talking about ghosts and such, when she began to explain to me about the duplex and why she moved.
Apparently I had not been the only one to experience the feeling of being watched. One of the scariest things she told me though was that her dog and constant companion, Choo-choo, had been almost choked by this ghost/demon/entity. They had been in the living room talking, when he suddenly jumped up and crossed to the corner. He stood on his hind legs in a begging position and whimpered and then his head twisted like something had a hold of his neck. He was shaking, but when mom picked him up and tried to calm him, he acted like nothing had happened.
The day after this conversation, we went to get some of the stuff in the house that had been left behind. My mother and I were outside waiting, while Vince was inside getting stuff. When he walked out, he told us of how he had gone to the bathroom and when he got out, the computer chair had been moved from one end of the house, to right in front of the back door. Now we didn't really have a computer chair but what we used as one, was one of the big, heavy, old-style armchairs. It wasn't exactly easy to move.
A month after this, we were talking with one of our previous neighbors, and he told us a little about the previous owner. Apparently he had been into a lot of devil-worshipping and black magic. I'm wondering if maybe it's a manifestation of his energy left behind, or something else entirely
BTW, my fiance is a practicer of Wicca too, and I know for certain that Celtic Wiccans tend to be very good clown with strong clownual traits. More than once my fiance has been able to clear negative energy and clowns out of my room. It sounds like your mom has protected you as well.