So far as, as far as light switches (or gangs) are concerned, they can only be certainly one of two things; a one way switch or a two way switch, end of.
One way light switch mechanism
A a method switch has two terminals, its the only of switch arrangements. it’s either on or off, thats all it does. When it’s ‘ONthe COM terminal is connected to the L1 terminal (let there be light!). When it’s ‘OFFthe COM terminal is connected to nothing and (the switch is open) no current flows through the switch.