If I were you, I’d call the local fire department and tell them your story and have them come and do a safety inspection with the express purpose of getting this sign thing fixed. God forbid (a thousand times) that there should be a fire and… well, you know. I’d skip dealing with your bosses or the building owner and anyone who might put it off, and go right to an agency that can make this change happen. [/Unsolicited advice]