Safety switches
Since mid-1992, all new homes are required to have a safety switch installed.
A safety switch is a special device that is intended to prevent people from receiving serious or fatal electric shocks. The switch quickly removes electricity from a circuit or appliance when it detects a low level of leakage current to earth.
For homes built before 1993, check whether a safety switch has been installed and if not, ask a licensed electrical contractor for advice about the type of safety switch that best suits your needs.
If you do have a safety switch, operate the test button regularly to make sure the unit is working properly.