I have installed the Light Switch, activeted it but not works. Why?
The Light Switch require to works at least jQuery ver. 1.7.2 (present since wordpress ver. 3.4).
Sometimes, also if you have installed a wordpress ver. 3.4 or higher, can happen that some theme load sadly a previous jQuery version, so that the Light Switcher will not works. In this case you can update the jQuery library in your theme with a recent jQuery version.