On Mon, 17 May 2010 23:56:13 -0400, mm wrote:

This would be about 9 cents a year, if the light is off all year.

Using California electric rates, I get, for a single switch, 31¢/year?

1switch x 24hours/day x365days/year x 35¢/KW x .1W x 1KW/1000W

We have tiered pricing out here where the first week or so costs about
11¢/KW, the next week is about double, and the last two weeks of the month
it's more than 4 times as much so I averaged that to about 35¢/KW.