I also agree with Abbey. Although I've not as yet run into any to fear, either. And I've had experiences since early childhood. I can't judge other people's experiences but I often wonder if the scary stuff is either made up or caused by ignorance and fear.
BTW my grandfather must have known I was talking about him. I've smelled his pipe all morning. lol
But I don't necessarily think it's a "not crossing over" thing. Many I've known haven't had a reason to lag behind. It's more like visiting. Most especially with family members and friends. Maybe this kid is hoping to see his family, time may not pass for him the way it does here and he just doesn't realize they won't be showing up. Or maybe he thinks it's a pretty place and just like to hang around.
Crazy? Nope. I don't think so. People can call me crazy all they want. I've had too many experiences to just dismiss it as imagination, coincidence, or anything else people attempt to excuse it away with.
Not to scare you.......but with a house with the history of yours and it's age.... odds are you're having more than one visitor.