I Saw A Black Shadow Moving Into The Living Room

I can't precisely remember the date it occurred, But I was alone in our house on a summer's night. I was stargazing in our backyard. After that I went back inside the house to my room and had left the door open for some fresh and cool air to come in.

After about 3 hours of being in my room I forgot I left the door open and thought it was time to close it because it was late in the night already. I went down the stairs, around the corner of the hallway (our hallway lights are broken) and I saw that I had left the second door open as well that leads into our kitchen. Now when I looked at that second door I saw a black figure about 60cm in height move like it was scared by me around the second kitchen door into the living room. And while I saw this moving I actually ''heard'' it moving, like footsteps and dragging over a wooden floor.

Now I thought this was my cat that was eating (as he is always scared of anyone) and running back to his spot in the living room. I turned on the lights and saw the cat was asleep. I really was not scared at this point because maybe its the neighbor's cat that came in (as I had left the door to the backyard open) however I could not see any cat or animal in the living room. I turned back into the kitchen. And when I wanted to close the backyard door, the lights flickered on and off for about 3 times (this has never happened ever before)

I seriously left the lights on, ran straight back up to my room and locked myself in there until my parents arrived from a night shift.

Now my mother does believe in ghosts and she has noticed some strange events in the living room like the radio turning louder and back.

And a boy sitting on the staircase.

I still can't tell if I believe in ghosts or not but I do always look twice anywhere if I'm home alone.

I would like to ask any of the readers to possibly have an explanation what was in the house that night.