Bedikat Chametz by flashlight - Yechaveh Daat 1:4

Rav Yosef here deals with what seems to be a fairly straightforward issue - can one use a flashlight or other electric light for bedikat chametz? His initial approach is to show that a flashlight does not constitute an avuka, or torch, as a torch by definition has separated wicks whose flames merge into one, while the various filaments in an electric light (the "wicks") are all combined. Rav Yosef further deals with the issues of whether or not the glass cover over the filaments constitutes a problematic barrier over the light (it does not) and whether an electric light can be called a ner, candle (it can, since it does for Shabbat candles). Rav Yosef therefore concludes that while a wax candle is preferable, an electric light can be used as well.