KiCad boards from 2 GitHub repositories tagged “relay-control”, the most starred first; open any of them in PCBKit.
k3ldar/PowerControlHub
PowerControlHub is a flexible automation controller for 12V systems. It combines relay switching, sensor monitoring, and smart‑home connectivity (MQTT, Home Assistant, REST, BLE) into one device.
Srushti-D-Hebbar/arduino-water-level-monitor
Arduino Uno water-level monitoring and pump controller with HC-SR04, 16×2 LCD, and relay-based pump control. Wokwi-validated and designed as a 2-layer PCB in KiCad 10.