Although the custom is not to say bircas shehecheyanu over the mitzvah of bedikas chametz, there are in fact some authorities who rule that one does recite it. Thus some are accustomed to take a new fruit and when saying the berachah shehecheyanu over it, have in mind that it is also for bedikas chametz. (see: Piskei Teshuvos, volume 5, 432:2)

Rav Moshe Sternbuch in his Hagadah “Moadim Uzmanim” discusses whether one should leave the electric lights on or turn them off during bedikas chametz. On the first year after I was married, I could not decide what to do in this matter. It was the electric corporation who finally decided the matter for me! When I began bedikas chametz there was power outage, but during the bedikah the power returned. I was thus able to follow both opinions! Since then I have followed this procedure each year, I begin with the electric lights off and then during the course of the bedikah, I turn on the lights.