Do you need to detect if light is present? This will change resistance if the area becomes dark, or light. Use this to detect if night falls, or if a light is turned off/on.
This is a photoconductive cell, or photo resistor that will change resistance if the light in the area changes.
The resistance will change from 1K to 10K (light to dark respectively). The photodetector can handle 100mW and a max voltage of 150V. Pin spacing is about 3.5 mm.