So, growing up, I had a childhood friend who lived in the same neighborhood as me. She was weird as fuck. Like really weird. She always said how she saw "bloody-dead" people in the woods and eventually got to the point where all the dads in the neighborhood went on an investigation to see what she was talking about. Turns out nothing was there besides beer bottles and hot pocket wrappers.
Anyways, during the time my parents got divorced, she got an imaginary friend named "Matt". She told me Matt didn't approve of my family and said she couldn't play with me anymore. I asked who Matt was and she said he was a boy with black hair and black eyes and he didn't like me. She never talked to me after that.
Anyways, her parents were still friends with my dad and they talked every once in a while. They informed me that Matt got "physical" and began to make noises and wake the parents up in the middle of the night with knocking at the door. Eventually, Matt had the capability to "control the lights" and whenever Matt was present, the lights would either flicker or go out.
And you know what my dad did? He invited their family to our house for dinner.
When she came over, my dad told me to go into my room to "catch up" which actually terrified me (note that I'm 13 and she is 10). We were talking when she just suddenly went deadpan and stared at me directly in the eyes and said "Matt is here." And sure enough, the lights started flickering. I have never ran out of my room so fast in my life.
I refused to sleep in my room for weeks because of that incident. I have never talked to her since then and her parents still apologize for what happened. If that's not paranormal, than I don't know what is.