A malfunctioning or burnt lightbulb usually means that someone is hiding in the room, ready to jump on our hero/heroine while he/she's busy hitting the switch or tapping the bulb.
When someone lights a match in a dark old house (etc) and the single match has as much power as a 1000 watt bulb! Alternatively, they light a match, and then light an old oil lamp which has a vast amount of power.
When people switch a light off, it will still be possible to see everything in the room, just in a slightly subdued/bluish colour...
Lightbulbs blow up when: something psychic happens; someone opens the power box, rips out the biggest cable, and touches it to the rest of the stuff in there; If the lightbulbs are in a row, they blow in timed sequence.
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