Just a room where you can enter it by in some houses theres just basically a string or something that you can interact with that turns it into stairs up, and you can interact with said stairs to turn back into string

or while in attic you could close the stairs/ ladder

That… actually sounds super cool. Like an alternate form of basements, as well as a semi-safe hiding place.

Potential loot : Boxes filled with tangled Christmas lights, photo albums, moth-eaten clothing.

Potential threats: Rats, survivor zombies (those who got to an attic, then died from their wounds), and giant mutated moths.