I just rented a house built in the 60's. The house smelled of smoke. I looked to close the flue but found the metal damper had been removed. There is a wire hanging down that extends up the chimney (I can't see where it ends). When I pull on it it seems very taught and I don't want to break it. What do I have here? I spring release damper at the top of the chimney? How do I close/open? Thank you!!