My door chime on my 89mustang has failed

Know my problem is I have been searching the entire net lloking for the location of the sensor and I get no info. Is thier anyone out there that might have the slightest clue where it would be located? I'm talking about the actual noise maker when you leave your lights on or when you leave your keys in the ignition. I need to know where that noise maker is so I can replace it. Thanks in advance.
Tony