In the FNaF SL Living room there's a lamp, in FNaF 4 there's a lamp that looks EXACTLY the same! Possibly (since you are playing as Micheal) after your little brother and your sister died and since your father is in jail, perhaps you still live in the house?
Could just be reusing assets. Like the Primary Control Module uses FNaF 3's lights in the Office Hall.
IT'S A FLOATING LAAAAAAAAMP!!!! I.imgur.com
You're right. Perhaps I thought a little too hard lol
Hey, you never know. And even the smallest things leave room for discussion.