to be lit (of a lamp, burner, etc.); to catch fire; to ignite; to be turned on (of a light, appliance, etc.); to come on
to turn on; to switch on; to light up
to ignite; to set fire to; to spark (an incident, etc.); to inflame (a situation, etc.)
to catch fire; to be ignited; to ignite; to flare up (of an emotion, controversy, etc.); to blaze; to be ignited (of a dispute, commotion, etc.)
leaving (a light, TV, etc.) on; leaving engaged (e.g. a key in a lock)
to turn on an electric light; to switch on a light