Incandescent lights usually do not cause a flicker problem since the light filaments generally do not cool quickly enough (and make the light dimmer) during the "off" time as the voltage changes in the AC power line.

Why would an incandescent light bulb flicker?

Incandescent light bulbs can stop working correctly for all kinds of reasons. Contact problems, faulty wiring connections, worn-out receptacles, or a bad filament can all cause flickering. ... They could also happen as the result of wear-and-tear, improper voltage, or bad wiring inside the fixture.

Do LED lights flicker more than incandescent?

Traditional incandescent bulbs have a glowing white-hot piece of metal that creates the light. When the dimmer switches the power on and off, the glowing metal starts to cool down and the net result is the light dims. There's no flickering. LED bulbs don't have glowing filaments.