When He Died It Stopped

We have an old farm in the north of Sweden. The place was called Sabekmorkka. My family has lived here for over a hundred years, for five generations to be exact. My grandfather was never a true believer, not for the paranormal and neither for religion, he just did his work and believed that everything had its explanation. I've always loved my grandfather, even thou he died when I was pretty young. I remember him strongly.

There are many secrets in my family (as it is in a lot of families, I suppose) but from about one year ago my grandmother told me about strange things that had happened. She mentioned that my grandfather had seen a young girl in one of the houses several times, and strange sounds. And they told me that some of their cats and dogs refused to go inside the house, and the animals that did always looked at the ceiling and looked from one side to the next, as if someone was walking on the floor above them.

This frightened me, especially since I heard the knocking on the walls and the door at the same time.

I have still not heard everything from my grandmother, it seems like she only wants to forget or she is just mysterious as she always is. Love my grandmother. However, they told me that nothing has happened since my grandfather died. But a week before they told me that some thing did happen. The weird door thing happened at night (or really early morning for some). My friend was staying over and we where brushing our teeth since we have no water running in the house we had brought a bottle with water and brushed our teeth on the balcony. To get to the balcony you have to pass my parent's room. When we passed my parents room the handle on their door was slowly pushed down and the door opened so I said "good night" and no one answered so I said "...or don't" and fell asleep in my room.

The morning after, I asked my parents why they didn't answer and they told me that they had been asleep all night and didn't know what I was talking about. They had not been sleepwalking; the wind can not push down a handle. I have no idea if this was something paranormal, and I hope it wasn't because I have to sleep in that house.

Please, can someone explain what has happened? Before this I could walk around in that house without being scared, but know I always feel watched even in the day. I hear strange sounds, knockings and other things, but this is just some days not every day.

Am I just imagining this, is there some natural explanation? Please tell me if this is paranormal or not. I hope not, I am terrified, I am not looking for attention, I just want to be able to sleep in that house without being scared.