A simple pedal, the two button footswitch for Fender amps. Schematic in comments. : r/diypedals
How to make a Guitar Footswitch - YouTube
DIY: OT Pickup Machine footswitch (now with final pics!) - #84 by Markel - Octatrack - Elektronauts
Amazon.com: Foot Switch 2pcs Guitar Effects Mxr Switch DIY Tap Effects Switch Footswitch Tap Tempo Effects Pedal Pedal Plastic Effector Black Guitar Tap Pedal Tempo : Musical Instruments
DIY: OT Pickup Machine footswitch (now with final pics!) - #84 by Markel - Octatrack - Elektronauts