Common On Light Switch. The next most common is the three-way switch, which is commonly used to control a light fixture from two different locations. When lights are switched on, there is usually only two possibilities on or off controlled by one switch.
It's not a common problem, but with old houses One of the black wires will bring power to the switch, the other will energize the light fixture; this is commonly referred to as, power in and power out. Flat white panel light switch on a white wall being turned on and off by a caucasian male hand closeup. Before go in details, we have to show the basic construction and operating mechanism of.
This method is commonly used now days as it is efficient than the Two Wire control system.
It's common (in my experience with amateur wiring at least) for this step to be omitted.
A wide variety of common light switch options are available to you. Referring to this diagram above, the ' common ' terminal goes to the red wire to the lamp in the left switch, and the black wire on the right side switch. The crackling sound heard when switching the light on is a 'common situation' within our building.