Her Body Parts

Chuck is convinced that his neighbors are space aliens. They walk funny, they talk funny, they never stop smiling, and he's seen them doing strange things in their tornado shelter in the backyard. Oh, and clearly the names for their human identities-Mariah and Carey-were stolen from some song they heard on the radio! However, his parents and coworker Bree shrug off his accusations. Chuck needs proof.
But when coming home from work one night and seeing them hauling around what appears to be a dead body upstairs in their house, he's so distracted that he doesn't see the oncoming truck... When Chuck wakes the next morning, he assumes it was all a dream. But something's different. His body might look the same, but now all of his body parts are detachable, and his insides have been replaced with robotic pieces.
Only two people on the planet could explain what's happened to him, and they live next door. And they're definitely not people...