I have a 3 year old 4 ft Normal Output AGA strip light and whenever I first turn it on it makes a loud buzzing noise. Once it heats up the buzzing noise grow much quieter. Then, after it is heated up, the vent holes start to become very warm/hot to the touch and they start to smell like very hot plastic and burning dust. Do you think it is safe to continue using this strip light or should I be worried about it starting a fire? Thanks.