Shut In (2016)

Recently widowed child psychologist Mary Portman (Naomi Watts) lives an isolated existence caring for her bedridden stepson (Charlie Heaton) in rural New England. But when a young boy (Jacob Tremblay) Mary is treating goes missing in a snowstorm and is presumed dead, she becomes convinced that his ghost is haunting her...and soon Mary’s grip on reality turns as slippery as her icy surroundings.