Many, and I mean many years ago, I read a model train article about how to build a simple electrical circuit using a piezo buzzer operated by a battery and the switch on the bottom of a refrigerator car for a refrigerator sound. There was a different size battery and different size buzzer depending on gauge. So, I'm looking for that article or, a circuit to build or buy that fits in an O refrigerator car, battery or track powered. Researched this and haven't found anything.
Thank you, Terry