I used to use it well, but recently I don t know why, turn on the switch of the living room light, a

This is the decoration process of the electrician construction process will be connected to the parallel circuit wrong, LZ decoration when the living room light is done double control bar, should be the living room light double control dining room is made of single hole. The problem is easy to solve, just open the switch panel and reconnect the wire.

[It can be determined].

The living room switch does not fall in place well when closed.

Solution] Remove the outer frame of the panel, adjust the switch spring, there may be dust, and it is not excluded that the wiring is loose, and you need to tighten the screws of the terminal.

In your case, you can conclude that there is a problem with the switch, you can remove the switch and put the control line inside to try it. If that doesn't work, it's best to let the worker who walks the line for you solve the problem.

The terminal is loose, string the wire. Tighten it and you're done.

It could be a problem with the living room lights.

Is your switch conjoined? Just change the switch.

Wiring problems.

Have an electrician check the wiring.