Breathe: A Ghost Story — Cliff McNish

Jack is not a normal boy. He can talk to ghosts. In his new home, an aging farmhouse, he meets the Ghost Mother, a grief-stricken spirit who becomes very attached to him…too attached. He learns that the Ghost Mother is preying in the cruelest imaginable way on four child ghosts who are trapped in the house, stealing their energy to sustain her own. Before Jack can figure out how to help them, the Ghost Mother takes possession of his real mother's body. Jack wants to fight back, but he has severe asthma and risks fatal attacks with any physical exertion. It will take all his resources, and his mother's as well, to fight off the Ghost Mother and save the ghost children from a horrible fate.