Have you ever thought of making sunlight controlled light bulbs? It sounds redundant, but it can automate anything when the sun is down without using a microcontroller. It has a photoresistor, or most commonly known as a light-dependent resistor(LDR) and a relay. This relay can be triggered on/off, depending on the surrounding luminosity. This relay module could hold up to 10A 250VAC and 10A 30VDC. The sensitivity or the luminosity level could be modified using the on-board potentiometer. You only need to power it up using a 5V power supply, and the component you want to control. There is no need for external devices like a microcontroller to make this module work.