I live in a 1980s mobile home with light switches and breakers as in the picture. If the switch is arcing or if the switch is held between on/off for a few seconds can this damage the breaker? The switch is a self contained type.
Arcing is not a good thing for the switch but it won't damage a standard circuit breaker. If the switch contacts are held at a point where they arc the arc starts damaging the contacts. With a older possibly Mercury switch where there is a glass tube with Mercury the arcing if held to the point the mercury vaporizes I have seen the glass tube fracture so a new switch was needed.