Wall switch is also divided into many types, single-control switch and dual control switch is more common, for these two switches, people need to have a correct understanding.
Dual control switch can be used as a single-control switch? Many people are not very understanding of it, the other for the double-control switch and single-control switch is to know the difference.
The convenience of double control switch is that it can control the electrical switch from two places, such as turning on the light switch downstairs and turning off the light after going upstairs. In fact, electrical switches and other electrical appliances by the two switches to control, that is, a switch with both normally open and normally closed two contacts.
This approach may be possible, but not recommended. When you open the ceiling single control switch (energization), others (case) but also to the dual-control switch and then open it, there is no load between the ceiling and the dual-control switch, which is always in the power,
The life of the wire is not good, as well as the life of the ceiling lamp is not good, but also electricity costs money. ——Yeslinkele.com