The Housemaid by Freida McFadden
Millie's new job is too good to be true. The salary is beyond her expectations, the house she'll be living in is gorgeous, and even if the attic room is cramped and dark it's a huge improvement over sleeping in her car. AND her new employers apparently didn't both with a background check. By the time she realizes just how erratic Mrs. Winchester's behavior is, she's determined to hold onto the job at all costs.
I can't get enough of Frida McFadden's domestic thrillers. They're fast paced and entertaining and a great way to spend a couple of hours. In this one, the plot shifts, then twists, then twists again. Millie is a likable protagonist and I genuinely cared what was going to happen to her in the end.
Disclosure -- The publisher provided me with an advance review copy. This post contains affiliate links.