John Carpenters "They Live" is probably what you're thinking of. Its the movie where the dude finds sunglasses and sees the world for what it truly is and the signs for stores and billboards have things such as "Sleep" "Consume" etc as underlying messages that normal people cannot see, even upon looking at certain people they're a skinless humanoid alien creature with the sunglasses, with them off they just look like normal humans.
John Carpenters "They Live" is probably what you're thinking of. Its the movie where the dude finds sunglasses and sees the world for what it truly is and the signs for stores and billboards have things such as "Sleep" "Consume" etc as underlying messages that normal people cannot see, even upon looking at certain people they're a skinless humanoid alien creature with the sunglasses, with them off they just look like normal humans.