#Zigbee light switches system
bronze widget
They have dimmers, on/off, and fan switches. The aux switch is meant for wired multi-switch setups so won't work for what you want, but any old wireless ZigBee switch stuck to a wall would work (I would start looking for Shelly or sonoff as brands I have used other devices from, but there should be a fair amount of ZigBee battery powered switches out there)