Nightmare Man (2006)

Ellen orders an African hand-carved mask from Rome to resolve her fertility problem with her husband William. After receiving a wrong mask, Ellen insists that the demon Nightmare Man is attacking her and she needs pills to keep him under control inside her, but the doctors diagnose her as a paranoid-schizophrenic.

On the way to be committed to the remote Devonshire Institute, the car runs out of gas and Bill leaves Ellen in the car while he walks to a gas station 10 miles away. Ellen is attacked by the Nightmare Man but she escapes through the woods, reaching the house of Mia, who shelters her and calls Bill, who reveals that she is delusional so they decide not to call the police.