Phone Guy appears in other FNAF games, not necessarily sister location. He's a very nervous kind of guy with unknown motives towards Michael. He might be helping him... or he might not be... If you'd like to play it like the voice in the game, that's perfectly fine! Or if you'd like to try your own unique take on it, feel free as well! I don't have a lot of vision for this since it will probably only be one line, so be creative!