I was walking through my garage and heard a buzzing noise and it sounded like it was coming from my 68 mustang. Sure enough, there was a little box in the front right corner of the engine bay kind of behind the horn that was making a humming/buzzing noise. I unplugged it and when I plugged it back in it stopped. I have a battery tender on the car but not sure if that has anything to do with it or not. What is this box for. I attached a picture of the part I am talking about.