Daf Yomi - Beitza 23 - Electricity

Rav Yehuda rules that placing spices on top of buring coals is prohibited since it involves the melochos of extinguishing and kindling but placing spices on top of a hot earthenware plate with the intention of smoking the fruits would be permitted. Rashi explains that there is no extinguishing in this manner and we are not concerned with the kindling which occurs when the incense ignites since it is done in an unusual manner and is not a Biblical melocha.

Rav Shlomo Zalman wonders as to what the halacha would be if one would turn on an electric light on Yom Tov in an unusual manner. It would seem from Rashi that it would be permitted since he permits performing a melocha in an unusual manner if it would be deemed to be necessary for Yom Tov.