I do think that sometimes ghosts, as in people, get to interact with the living... but only rarely and under circumstances I don't know.
But all of the ghostly paranormal activity that's so popular is demonic. And demons do haunt houses FYI.
I spent the night at a friend's apartment for the first time one night and she didn't say a word to me but I figured out on my own we weren't alone. The rat grabbed my leg and swung it to the side while I was trying to sleep. -_- It wouldn't let up so I kept vigil all night, praying over the family and myself. The next morning, she told me that she and everyone had the most peaceful sleep they ever had in that apartment then cautiously told me about how she had a pastor over to cleanse their home because she thought it was haunted. I was like, yeah, I know. I prayed. (I was a smidgen grouchy because demonic activity angers me and I missed out on the peaceful sleep part.)
The reason why I'm sharing is because too many people are attacked and don't defend themselves. And don't rely on holy water and crosses, those things have significance by association but at the end of the day... holy water didn't win the war, God did.