illuminated switches?

[Doug Lasiter]

I have a ceiling fan/light with a dual switch on the wall. Curiously, the wall switch for each is illuminated IF the light or fan are turned on with the pull chain. If the pull chain has the light or fan turned off, the switch illumination for the light or fan is off. I have another fan/light whose wall switch is always illuminated whether or not the pull chain is off or on. What's going on here? Is this a special switch that senses whether the fan/light is turned on with the pull chain?

 

[littlespark]

The first switch has its light wired on the switched side… the second switch has its light wired into the supply side… so it doesn’t matter if ceiling light is on or not, the switch illumination will be on

 

[Doug Lasiter]

So how do you establish, when you buy such a switch, how it is wired? Luck of the draw?

 

[James]

They are the same switch connected up differently.