Over the years I have owned many hundred vintage Japanese guitars with these rocker switches. They were common on Japanese manufactured guitars throughout the sixties (and some in the seventies) and have been asked many times to "replace" them, when they're not working properly. Unlike a lot of more modern switches, these can be completely rebuilt and in most cases, serviced to go for another 50 years if treated properly.
These particular ones are on a mid sixties Guyatone, but the other big brands like Teisco, Teisco Gen Gakki, Suzuki, Matsumoku, Kawai etc all used the same, or very similar switches, and most can be stripped and rebuilt to function perfectly.
Japanese guitar electronics get a bad wrap in some circles and for no good reason. The electronics on most of these medium to good quality vintage Japanese guitars were superb and by the seventies, Japan was making some of the best electronics (not just guitar but consumer) in the world and by the eighties dominated the electronics manufacturing world. I work on A LOT of these vintage Japanese guitars and most will still function perfectly with all the original electronics after a good service and clean, and this is after 50 years of use and neglect.
These rocker switches were mainly used as ON/OFF pickup switches although some brands used them as tone switches as well. The execution is the same either way although some of these do have contacts on BOTH sides of the rocker for more options, but most (the vast majority) are a simple make or break switch.
There are two blade contacts that touch each other to complete the circuit, in this case, the pickup to the volume and tone pots (and out to the jack) and the switch body rocks on a round shaft, and a small "blade" of plastic formed into the rocker body, separates these contacts, breaking the circuit and switching the pickup off.
The switch bodies are heavy folded metal and the round shaft slides into a hole at each end. The body (on this one) is made for three rockers as many of these guitars were offered in one, two or three pickup versions. There are switches with more (up to eight was not unheard of) but most of these are three rocker with either three, two or one rocker depending on the model.
The "tension" of the rocker is applied by folded brass brackets that sit under the round shaft and "push" on the rocker body. If you find these switches are loose and rock too easily, you can carefully bend these brackets to bring some tension back into the switch.
I advise running a bit of wet and dry between the contacts before putting everything back together and give it all a good dousing of a good quality contact cleaner and lube before reassembling back into the scratchplate/guitar.
The metal bodies are threaded to take the small screws that attach it to the scratchplate and the contacts are generally soldered to eyelets set in good quality thick phenolic board.
Being able to completely disassemble these switches is great to keep them going and unless they are actually physically broken (or lost) they will keep on working for years to come.