Wiring Harness for Illuminated Metal Push Button Switch [WH] - $4.34 : Auber Instruments, Inc., Temperature control solutions for home and industry
L1: Using buttons - Physical Computing
Chapter 5: Add a button – Arduino to Go
Button wiring and declaration with the esp8266 - General Electronics - Arduino Forum
5Pcs 19mm 12V Waterproof ON Off Latching Push Button Switch with Wiring Harness and Led Indicator Light, 24V Pre-Wired SPDT Self-Locking 4 Pin Marine Metal Switch for Boats Cars Truck (Blue): Amazon.com:
SIK Experiment Guide for Arduino - V3.2 - SparkFun Learn
Arduino: Pushbutton
Push Button Switches - VIGO Horizontal - Lumeno LED