My in-laws have a multi-chime electronic doorbell about 15 years old. Recently, it has taken it upon itself to ring randomly.
Door button has been replaced and wiring appears to be sound. I don't believe there's a short between the chime and the button because it only rings once; were it a short, it would ring continuously (I tested that).
Is it more likely to be the transformer, the circuit board, or something else?