Help! I think theres an animal in my fireplace?

I have an old wood stove in the house that's not in use until it gets colder out. I was home today and noticed scratching and running sounds coming from the room where my stove is. I'm afraid to open wood stove door and have some kind of animal jump out at my face. What ways can I get this creature back outdoors? I don't want to kill it, I just want it outside.