The house I grew up in was occupied by the ghost of the previous tenant, let's call him Joe. We were on fairly friendly terms with him, he responded to his name and everything. He initially mostly liked to play tricks on my eldest sister, turning things on or off in her room, swinging her door open wide in the night, ruffling her curtains when the windows were closed etc. When she eventually moved out and I took over her room he would do it to me instead. It never felt malevolent, always felt very much like a practical joke IYKWIM. None of us were ever afraid of Joe.
Joe slowly got less and less active as the years went on but a few incidents occurred that confirmed for us all that he was friendly and looking out for us.
My other older sister was asleep in the living room one night and was suddenly awoken by my Dad's lathe turning on in the basement beneath her. She got up and turned it off and as she came back upstairs heard water running. Turns out a pipe had burst in the downstairs bathroom and water was slowly flooding the house so she woke my Dad up and he fixed it. We think Joe turned the lathe on to wake her up on purpose. If he'd woken anyone upstairs up they may not have heard the downstairs pipe leaking.
One incident was one morning when my eldest sister and I were in my younger brothers bedroom hurrying him to get ready for school. He never used to bother with his curtains and they mostly just stayed half open, never fully open or closed. Anyway we were talking to him when suddenly his curtains swung open very violently. The windows were closed and there was a bed between the 3 of us and these curtains so it definitely wasn't any of us. Anyway we all jumped and then stared, seeing our next door standing on top of his kitchen roof peering into my brothers bedroom! He looked as shocked as us! My Dad went totally mental, round there within minutes hammering on the door and calling him a paedophile etc.. neighbour claimed he was checking the pipes and police refused to take it any further. We've always thought Joe had opened the curtains to alert us to the peeping Tom.
Another incident was when my eldest sister brought a boyfriend home for Christmas. Joe really dislike to him. We hadn't actually mentioned Joe to this guy as this was later on when he'd gotten really inactive but the boyfriend complained repeatedly of being poked and feeling small pushes etc. Not playfully like he had with us as children but actually hurting the guy, leaving marks and stuff. At one point the boyfriend was having a quiet row with my sister and went to follow her out of the living room when my mum and I saw the back of his shirt lift up and he was dragged back into the room. I knew then that it was Joe and he was trying to scare the guy off. This boyfriend turned out to be a right nasty, controlling, violent piece of work.
These aren't the only things Joe did, there was lots of other stuff that we've never found an explanation for. I'm not especially woo about things, I do believe the vast majority of woo stuff has rational explanations. But at the same time I firmly believe in Joe.