“The Unfamiliar” (*1/2 out of four) was a dreary horror thriller about a British army doctor (Jemima West) who returns home from a war and thinks she has PTSD but soon finds that there is a mysterious malevolence in her life that has overtaken her and is threatening her and her family. Ironically titled time-waster is actually very familiar and is simply an amalgam of ideas borrowed from “The Exorcist” and “Paranormal Activity.” West’s sincere performance fails to enliven or enrich the proceedings.