Starman(1984)

An alien's ship crashes on Earth, and, to avoid detection, he transforms himself into a physical replica of the deceased husband of a young woman, whose house is the first he comes upon in the woods. He then must assuage her fears, learn how to adjust to his human form, and use her help to get to the Arizona crater where the mother ship awaits him. Things get's complicated when the two fall in love and the alien is pursued by government agents attempting to capture him.