I will try to be as specific as possible writing down this story, although being new to this kind of thing, I do not specifically know what details are important and which ones aren't, so excuse me if it's too long.
I live in a very old house - originally built somewhere at the end of the 1800s. The house has been renovated since and two new rooms were added in addition to the original house that had only one room. That one room, the oldest one, is now my bedroom, and it used to belong to my great grandparents. We have a front and a back porch, as well as a pretty big vegetable garden surrounding the house. My grandparents use to have pigs, chickens and rabbits, and behind the house there is a big shed for animals and housework that needed to be done outside, tools etc.
I remember that a couple of years ago my father got some firewood for a very cheap price, and decided to convert the fireplace in his and my mother's bedroom into a wood burning fireplace. That wasn't very practical as it somehow made too much smoke, but that winter they still used up the wood. My father used to always chop the tree stumps he had into smaller pieces, for firewood, behind the house. He had an old looking, bigger stump, on which he placed the wood to be chopped. So the sound of chopping pieces of wood that are placed on another piece of wood is somehow distinctly in my memory.
A couple of months, maybe half a year ago, I started staying up until late at night/early in the morning to study for my finals. On one occasion, after midnight (not right after, I do not recall checking the time, but it was really late) I heard a couple of knocks that seemed to be coming from outside, as I was typing away on my computer. The typing also makes a kind of knocking sound, so I wasn't sure that I actually heard something or not, so I stopped typing and heard it again, a couple of times. It reminded me of the noise I heard when my father used that stump to chop wood. The knocks weren't loud but you could hear them, and they were coming from the direction of my window, which is right next to our backyard and the shed. The knocks lasted for about 10-20 seconds, approx. 2 seconds apart from each other (the pause between each was pretty much the same on every occasion, similar to a clock, but the pause lasted 3, maybe 4 seconds). I don't recall this happening every night, but I also very often spend a couple of nights at my boyfriend's place, so I am not home every night; however, I do recall hearing this repeatedly, maybe 5 or 6 times (on different days), and no, I never opened the window because it's dark and there is no light there (so couldn't see anything anyway) and I was kind of scared.
Since then I read somewhere that there's this thing called residual haunting, where the repeated actions of a deceased person somehow stay in the home, and others can see or hear them - I have no idea whether this is true at all or true in my case, I just thought since my great grandfather, great grandma and my grandfather (all 3 of them dead) were all basically farmers that chopped wood on a regular basis, it is a plausible explanation.
Hope you could understand this. I am happy to answer additional questions if you have any, and I would really love some more insight on this!