The answer to 'how long does switch last' is that the average lifespan of an electrical switch is around 10-20 years, depending on usage and environmental factors. Switches are designed to withstand regular on/off cycling, but over time the internal components can wear down, leading to failure. With proper care and maintenance, switches can often last even longer.
Factors that can affect a switch's lifespan include the quality of the switch, how often it's used, whether it's exposed to moisture or other environmental stresses, and whether it's overloaded or used beyond its rated capacity. Proper installation and avoiding physical damage are also important for maximizing a switch's useful life.