My First Ideas For a Horror Story.

My first ideas came from an "Amityville" horror-eske movie with some concepts from "The Strangers".
" I first thought about a family who who owned this particualr house for generations. To create a background history/horror, all people that were living in the house, died of unknown causes. There was also no evidence that they commited suicide or murderd. I thought this create a decent background story for a horror. A few years after the incident, the house goes up for a sale and a new family move in. They have no knowledge of the previous owners and what happened. They live in the house for several months and everything is fine. They go to work, go to school, come home, eat etc. Everything is normal until one day the mother of the household finds a cuddly toy laying in the middle of the main living room. She has never seen it before. She picks it up, moves it and ignores it. The mother goes to work, comes home and finds the toy in the exact same place as she did when she left. No one has been in the house. She moves the toy again, and ignores it.
When everyone is home, everything is fine and normal.p They all go to bed as normal but the mother hears quiet knocking noises on the back door. She doesn't know if she is imagining or not. She asks her husband to see if he hears it. He cannot. The mother asks him to go downstairs to find out what it might be. The mother stays up stairs to wait for his return. He never returns."

These are my first ideas of a horror story but when I have to make a horror trailer, I don't think this could be very possible as I would have to find a couple of families and a free house.