WORRIED (VERY)!!!!

hi everyone i decided to join this forum cause something is really freaking me out. well lemme explain. im at my study desk on my computer and i see the curtains blowing. ok so the first thing that comes to mind is to close the window. i do that , then get a quick drink / toilet break from homework. and what do you know the windows open again.... i didnt even realise it was open till at night it was very chilly. also when i go to sleep i hear creaking noises on the ground in the house. in the kitchen mostly. our house is wooden flooring and is constructed in planks andd is about 60 years old now. when you walk or sneak around it creaks which is normal. BUT NOT AT NIGHT WHEN NO ONE IS AWAKE!!!! pls someone help me im freaked out.. currently typing this i feel someone is behind me which also makes me nervous ... thnx for listening guys. help would be apprecaited.

Has any family memeber that you know of died? They could just be there with you though i dont see why they would open the window again. Your very brave cause the kitchen is literally right next to my room and if i heard footsteps in the kitchen i would be SOOOOOO freaked out i would probaly run to my mums room and turn on all the lights. i get scared easily...

Do you know if the people that owned the house before hand, whether any of relatives of theirs or one of the owners died?

Sorry, those are the only suggestions that i can think of... unless somebody u know has died.

If the windows were only slightly open i would suggest since the house is older that the windows just do that. Even if you've never noticed it before, the atmospheric conditions could have been just right that the moisture in the wood or the settling of the house caused the window to slide a little bit. I'm assuming that since you didn't notice until later that it wasn't open very far. As far as feeling someone behind you, turn around. Try to position yourself with your back to a wall or something solid, it is common when your back is to a wide open space to feel as if something is there. I would say the sounds at night are also the house settling. Wood floors have a tendency to expand and shrink throughout the day depending on the humidity and temperature. Could be at night the wood gets cold and shrinks enough to make some creaking sounds.