The Invaders(1967)

David Vincent has seen them...

The Invaders is a science-fiction series following David Vincent, an ordinary man who stumbles upon an extraterrestrial conspiracy. After witnessing a spacecraft land on a remote country road, Vincent discovers that aliens from a dying planet have arrived on Earth with a sinister goal: to infiltrate human society and claim the world as their own. The invaders can assume human form, making them nearly impossible to detect. Desperate to expose the truth, Vincent races against time to warn a skeptical public of the impending threat. Alone and hunted, he becomes humanity's unlikely defender against an invisible enemy determined to conquer the planet from within.