electric switch. The toggle light switch was invented in 1916 by William J. Newton. As a component of an electrical wiring or home wiring system, the installation of light switches is regulated by some authority concerned with safety and standards. In different countries the standard dimensions of the wall mounting hardware (boxes, plates, etc.) may differ. Since the face-plates used must cover this hardware, these standards determine the minimum sizes of all wall mounted equipment. Hence, the shape and size of the boxes and face-plates, as well as what is integrated, varies from country to country. The dimensions, mechanical designs, and even the general appearance of light switches have changed slowly over time. Switches typically remain in service for many decades, often being changed only when a portion of a house is rewired. It is not unusual to see century-old light switches still in functional use. Manufacturers introduce various new forms and styles, but for the most part decoration and fashion concerns are limited to the face-plates or wall-plates. Even the "modern" dimmer switch with knob is at least forty years old, and in even the newest construction the familiar toggle and rocker switch formats predominate. Orientation The direction which represents "on" also varies by country. In the US, Canada, European countries, Russia, etc., it is usual for the "on" position of a toggle switch to be "up", whereas in many other countries such as the UK, India, Australia, New Zealand (Commonwealth countries) and Ireland, it is "down". (In multiway switching, the correspondence between a single switch's state and whether lights are on or off depends on the state of the other switch[es] in the circuit.) Design The switches may be single or multiple, designed for indoor or outdoor use. Optional extras may include dimmer-controls, environmental protection, weather and security protection. In residential and light commercial lighting systems, the light switch directly controls the circuit feeding the lamps. In larger lighting systems, for example warehouses or outdoor lighting systems, the required current may be too high for a manual switch. In these systems light switches control lighting contactors, a relay that allows the manual light switch to operate on a lower voltage or with smaller wiring than would be required in the main lighting circuit. In the UK, putting 13 amp BS 1363 sockets on a lighting circuit is discouraged (although not outright prohibited), but 2 amp or 5 amp