A book about a teenage boy named Bart or Burt. He and his little sister (maybe more than one sibling) and their parents recently moved into a new house.
Bart/Burt used to be a bookworm and nerd but is now a high school football star. Strange things start happening in his home and he finds out that his home is full of ghosts, including a girl about his age and a poltergeist.
Bart/Burt helps the other ghosts stop the poltergeist and they help him win in football.
I can see the cover art in my head. A teenage muscular boy with his arms bent at the elbow and hands raised so the backs are parallel to his chest. A ghost girl in historical clothing in the same position so they are pressing their palms together as they stare at each others face.
But for the life of me I can’t remember the title or author. I remember reading this book as a preteen and am not sure when the book was printed, I really want to say some time in the 80’s but it may have been the 70’s or very early 90’s. But my gut says the 80’s.