Pale Blue Moon (2002)

A detective is assigned to transporting a homeless man to a psyche ward after he was caught tampering with a radio tower to block alien communication to the moon. The man claims he must kill a big-time media mogul whom he believes is an alien leading the extermination of the human race. The detective must decide to either stop this man's insane mission, or to believe him in order to save the planet from the coming invasion.