Noise coming from glove box when car is running what could it be

Without knowing what the noise sounds like, your best bet would be loose items actually in the glove box, or something in the heating system, like a weak valve fluttering. Does it make a difference if you have the heater or a/c on or off? Does it matter if the fan is on or off? Do you hear it sitting still or moving? These are all questions that need to be answered in order to track it down. It is usually fairly simple to remove the glove box itself and locate where the sound is coming from.