Siamesecat, I do a lot of my forum posts at work too. Shhh....
I've never had anything sudden at night, but I have heard things in my mom's house. When I come home and there's nobody there, I can hear something coming from inside. It sounds like a cocktail party, or a radio or TV on quietly. The second I touch the door handle to unlock it, the sound goes away. And sometimes when I've been in the basement when I was home alone I'd hear it too. I've frequently talked to the empty house. I'll tell it "Okay, I'm home now, time to be quiet" in a nice tone, or remind it to please cut out the noise, it's freaking me out. And when I'm leaving for a while I'll make sure to tell it that noise is okay now.
I don't know what it does now that my dog lives there. I haven't heard anything lately, but I can still feel a presence there.
That house has always had spirits. Things would disappear and reappear. I've always felt that there's a little boy there and his dog, and get the feeling that he just wants to play with us and can't except by taking our things. One time, way back before computers were normal, my dad was in college and had a paper to write. My mom had typed it up for him on the typewriter and set it out for the morning so he could take it to class. But it was gone. Nowhere to be found. My dad went to class empty-handed because the paper HAD to be typed, but he swore he'd have it the next day, my mom had said she'd re-type it that night. After dad got home from work (after school) and mom brought the kids home from school and such, it was on the living room table. Nobody had been home all day, nobody else had a key to our house, there was no valid reason for it to have been there. They would have SEEN it that morning.
Another time several years later we had a girl scout meeting in our living room. One of the girls in the troop was our next door neighbor, and she had come over a bit early to do some studying. We let her use our computer from time to time. She had brought over an encyclopedia with her. The 'C', I believe, which is one of the biggest single books in the set. It's huge. When it came time for everyone to go home, the book was gone. It wasn't in the computer room, it wasn't in the living room anywhere, we pulled apart the couch looking for it. My younger sister (the one I talk about the most on here) and I had been in our room all night, and our older half sister (no longer in my life) was part of the troop. It was gone. We told her to go home and we'd get it back to her as soon as we found it.
The next day, after school we found it. On top of the refrigerator. Nobody had even been in the kitchen that night, and the only people in the house who could have reached that would have been my parents. And I think they would have remembered putting it up on the fridge and just given it back to the girl, especially over taking everything apart and spending half an hour looking for it.