This is the switch with cover
And this is a switch without cover.
This may look familiar to Europeans, but I think it will look very unfamiliar to our American friends. This is a watertight switch, and the blue arrow is just there to show the way the water flows through the switch. But all switches, be they outdoor, indoor, in wall or on wall, have the same red 'core' with six terminals. There is however a range of different switching configurations to choose from. Two/three way, four way, double pole and so on.
I'll leave it to you to figure out how to wire this beast. And can you figure out what 2+1 means?