In 1995 my dad and stepmom bought a house in a small town, Portland, TX. They took my older sister (15), brother (11) and I (7) over to look at it. The minute we set foot inside I noticed how dark it was. There were windows everywhere but it still seemed very dark.
My sister and I were to share a bedroom upstairs, while my brother took one downstairs along with my parents. I don't know how long after we moved in that things started happening.
The door to my room would sway back and forth at night, not a lot but an inch or two even when there was no a/c on. I always slept with a nightlight on and there were several instances when I would be lying on my stomach and thought one of the cats (we had two cats and three dogs) was sleeping across my knees but would see no shadow cast from them on the wall. I would also awaken to hear things in my room moving on my desk or dresser or a sound that I tried to convince myself was one of the cats making noises in their sleep but it would fade and when I would finally get the nerve to look the cats weren't anywhere in my room.
I started having horrible vivid nightmares of different family members becoming possessed and trying to kill me. Nightmares became a nightly thing for me. I remember one nightmare the spirit had possessed our Great Dane, who was too old to get up the stairs, but in the nightmare I woke up paralyzed in my bed and the great Dane was standing next to my bed and the spirit was speaking to me through her saying how it was very easy to possess a simple creature and that eventually he planned to possess me but that he wasn't strong enough yet.
While living here our other dog bit my face one day while my parents were at work when I was ten. I ended up with 7 stitches and three scars across my left cheek. On several other occasions after this the dog would snap at my face for no reason.
When my sister started her senior year her and my father got into a big fight (my father became increasingly angry and violent while we lived there) and he sent her to live with my grandma in the next big town over. So my parents moved me into my brothers room on the first floor (turning mine and my sisters old bed into bunk beds) and my brother moved up into the room that my sister and I had shared. He never believed me about the door swaying at night until he moved up in that room, then he witnessed it for himself.
Once my brother and I were home alone watching TV in the living room when we heard a loud thudding across his room upstairs. It sounded like a gorilla was running across his room. Another time we kept hearing thuds and bangs coming from upstairs and he went to call my dad because we were scared and when he picked up the phone there were strange voices on the phone talking in a strange language.
Another time I was having a nightmare about the house and woke to my bed shaking almost as if someone was under my bed pushing it up with their feet. My brother had a lot of the same experiences I did. I would wake up often thinking my cats were laying at the edge of my bed but when I would get the courage to look they weren't there.
One morning I woke up shortly before my alarm was to go off before school and heard a man and woman's voice talking in the bathroom (my bathroom was directly across the hall from my room and my parents weren't awake) I heard them for a minute without being able to tell what they were saying before I heard the man say " we need a new bathroom". Then a few minutes later my alarm went off and I jumped up and turned on the light.
Our back door was sliding glass and as with most sliding glass doors there was a lever that had to be lifted to lock it. Several times my brother and I got locked in the backyard. If I was ever supposed to be home alone I would take a bunch of books and things to keep me entertained outside so I was not inside by myself until I was older.
We always felt as if the upstairs was where it dwelled. You never felt comfortable up there and I couldn't walk past the stairs at night without feeling like being watched. We would try to tell my parents but they never believed us, they thought we were trying to get attention.
My parents owned the house for ten tumultuous years before they decided to sell it. My stepmom and I moved into a condo on the other side of town and would make trips over to get it prepared to sell, painting and repairs. Once while in the master closet the bedroom door slammed shut. My stepmom was upstairs painting a closet so it was not her. We also got locked out the front door once while working on it. There may be other instances I've forgotten, after I talk my brother I will add any I've forgotten.
Although, I really believe what you experienced was scary and paranormal, I have a theory about the phone line. Could the lines have been crossed? It has happened a few times in my previous homes where either I would be talking to someone and then all of a sudden there would be two other people talking or when I pick up the phone to dial someone there would be already two people talking; sometimes we won't understand what they are saying because they are talking in another language.