Disorder (2015) on Netflix

Plot summary

Vincent Loreau is back from Afghanistan, where he served in the French Special Forces, and he lives with post-traumatic stress disorder. A wealthy Lebanese businessman engages him to keep watch over his wife Jessie and her child at Maryland, the family's property on the French Riviera, while he is out of town. In the calm of the house Vincent feels a pull toward the woman he has been hired to protect, and his attention stays fixed on her. He is also given to anxiety and to hallucinations, and in the quiet around the villa he senses a threat coming from outside.