You read the title right, it's an actual mod for Fallout New Vegas that is meant to recreate the gameplay of Five Nights At Freddy's.
When you install the mod, a new Vault can be found in the top-center part of the map. In this Vault, you'll find the Arena - a place to test your skills and see how well you do at survival (no, not the skill). Can you make it from midnight to 6 AM without dying from radiation or crazy robots?
And unlike the other FNAF games, you aren't stuck in a single room this time... now you have to MOVE.
Due to various complications during development, this mod currently has no storyline, no "official" nights and no more than 2 robots. Because of those complications, I'm not sure if these elements are even going to be included at all. Still, for what it's worth, the current version should keep you occupied for an hour or so.
Please let me know about any bugs or problems!