I had a HUGE electricity jump a couple months ago. At first I thought it was from my lights but it turns out it was a room heater. when the fan kicked off the heating element remained on. Non-stop.

My point is don't assume it's the light. Anything in your house that uses electricity can malfunction and start your meter spinning.

Go outside and watch the wheel on your meter at the time when your lights switch off. See if it slows down when they shut off. If it doesnt then start flipping breakers off until you find which breaker slows it down when shut off. Then find whatever appliances are on the breaker and check them out.

Laterz