In-line power switch for 2.1mm barrel jack : ID 1125 : $2.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: 387874 RV Electric Stabilizer Jack Switch Compatible with Lippert High Speed Stabilizer Jacks, Power Stabilizer Jack Extend Retract Switch with Harness & Extra Terminals | IP66-rated Waterproof, Black : Everything Else
DC Power Jack With Horizontal Rocker Switches - Multi-Function Switches | Made in Taiwan Electronic Switches Manufacturer for Components & Accessories | DAILYWELL ELECTRONICS CO., LTD.
Amazon.com: Two channel Audio Switch Box 1/8' 3.5mm ab Speaker switcher TRS & TRRS Switch Headphones jack : Electronics