(Inspired by an animation made by Halo12. Go check them out, they make really cool mlp horror stuff. But seriously, this is essentially just the premise of the video game That's Not My Neighbor, but the residents are normal ponies, and the doppelgangers are changelings. You are the doorpony that must verify the identity of the residents and contact the CCC whenever you suspect a changeling is attempting to enter the building. Changelings can perfectly mimic a pony's appearance, but not their personality, so questioning them should be enough to get them to crack. If they do, hit the panic button and call the number of the CCC, 3312. I wish you good luck. You may also use an oc if you wish, but please keep it pony related.)