So, a bit of background. The house I currently live in, we moved into about 7 years ago now. I live with my parents and two brothers (I'm in my early 20s and my brothers are 18.) We live in a place called the Wirral, it's a little peninsula over the water from Liverpool.
Ever since we moved in there has been periodic episodes of strange activity. Like, things will happen quite frequently for a few weeks or months and then be quiet for up to a year. Some of the things I've experienced personally are the sound of light switches turning on and off or footsteps upstairs and wardrobes opening when nobody else is home. My dad and myself have also experienced the sound of footsteps running up the stairs and thought it was each other but it wasn't.
One of the more... "vivid" experiences was the smell of tobacco in our dining room. Like really strong pipe smoke, as if somebody was in the room smoking. This only ever happened once but it's stayed with me. It turns out that the previous owner of the house smoked a tobacco pipe. He, and his grandson who lived with him, both died while they were living at this address. So I'm thinking it may be them letting us know that this is their house and they are here to stay.
The activity seems to be more frequent during summer months (when the grandson died, playing cricket) and more sporadic and random during winter months. All of us have experienced something in this house, including the dog. She will quite often stare into space as if she's focusing on something intently. Luckily we have never felt threatened by the activity or by the sense of their presence in the house, it just feels like part of the house. We have never actually seen anything, I think I'd draw the line there, that would scare me.
Has anybody else experienced something similar in regards to the sporadic and fluctuating frequency of paranormal events? If so, why do you think that happens?