Relic (2020) on Netflix

Plot summary

Kay and her daughter Sam travel to the remote family home after Edna, the family's elderly widowed matriarch, goes missing. The house is locked from the inside, and black mold covers a wall upstairs. Reminder notes for Edna cover much of the furniture. Their young neighbor Jamie says his father no longer allows him to visit. Creaking comes from inside the walls, and Kay dreams of a withered corpse in a shack in the woodlands. Edna returns barefoot and muddied, unaware of her own disappearance. A doctor finds her mostly lucid, though a black bruise on her chest resembles the mold. Kay wants to move her mother into a retirement home, a plan Sam rejects.