Answer:
I am a box who holds keys but not locks. With the right combination I may unlock your soul
I am shared by goats devils and unicorns.
I go from house to house a messenger small and tight. Whether it rains or snows I sleep outside at night.
While you were folding a letter you got me. Usually you will do whatever it takes to avoid me but now you can't help but find me.
I run up and down the stairs without moving
What is yours but only used by others?
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic