These are devices for breaking the flow of current. Switches come in various shapes and sizes, but all operate on the same principle. An important factor when choosing a switch is its rating. A reputable manufacturer will always indicate the operating voltage and current rating. For instance, a light switch must not be used as a stove isolation switch, simply because the rating of the light switch will be too low for the stove current drain, causing it to overheat and fail. Switches in a residential building would include switches in the distribution board, and the common switches indicated in the following figure.