The answer to 'flickering emergency electrical service' is that the most common causes are loose connections, faulty wiring, or an issue with the emergency power supply. Symptoms may include the lights flickering or dimming, or the emergency lights not turning on at all. Solutions can include tightening connections, replacing faulty wiring, or checking the emergency power supply and battery.
If the flickering is limited to the emergency lighting circuit, it's likely a more minor issue that a homeowner could potentially fix themselves. However, if the flickering affects the entire electrical system or you're unsure of the cause, it's best to call a licensed electrician to diagnose and repair the problem to ensure safety.