Standard SPST (Single Pole Single Throw) switch that was used, in this case, to arm the gun and gun-camera solenoids. It closed the circuit between the guns and gun-camera with the gun trigger switch. Some aircraft had one switch that armed all gun solenoids (P-47 according to my Pop) while others had one for each gun (F4U-series left console Ref: Whistling Death).
The AN is the old part numbering system and was the abbreviation for Army-Navy. Now we use MS (Military Standards) and are slowly evolving to standards like NAS (National Aerospace Standards). All of them are being identified and described in applicable ASTM (American Society for Testing and Materials) specifications and will culminate in one standard for products and materials. Unfortunately, the old specs are free (public domain) on-line in most instances. ASTM documents must be purchased.
The topic switch can probably be Googled by its AN spec number. Responses will also probably reveal its national stock number for similar products.
Edit: The red guard over the switch is not part of the switch. It's an accessory. The switch itself looks like an old Cutler-Hammer standard. Same for the guard. The guards were obviously designed to prevent unintentional closing of the switch or they were used to "capture" the switch to prevent unintentional opening of it. I work with this stuff all the time as an A&P.