The 23-year-old man, who has a history of mental illness, fired two pistol shots through his apartment window before opening fire from the window at what he imagined to be were alien invaders.
According to the Dale-Demokraten newspaper, the gunman said one shot hit a UFO, causing it to explode.
A woman who was in the apartment at the time of shooting in the central Swedish town of Hedemora called the police.
Despite the presence of armed officers it took the police several hours to convince the Swede that aliens had not earmarked him for abduction and that he was safe. The shooter, who has not been named, was later charged with illegal possession of a firearm and threatening a police officer.
“We do not believe that the threats voiced were anything other than the desperation of a confused person,” said local police in a statement.