Plan 9 from Outer Space (1957)

In California, an old man (Bela Lugosi) grieves the loss of his wife (Vampira) and on the next day he also dies. However, the space soldier Eros and his mate Tanna use an electric device to resurrect them both and the strong Inspector Clay who was murdered by the couple. Their intention is not to conquer Earth but to stop mankind from developing the powerful bomb "Solaranite" that would threaten the universe. When the population of Hollywood and Washington DC sees flying saucers in the sky, a colonel, a police lieutenant, a commercial pilot, his wife and a policeman try to stop the aliens.