The Halacha requires performing Bedikat Hames, searching for Hames, the night before Pesah. Any place prone to having Hames must be searched. In a house with little children, the entire house is considered prone to Hames, since the children are likely to bring Hames all over the house. Pockets, under the beds and school bags must be checked. This includes all closets, coats and cars. This includes all residences in which a person lived within thirty days of Pesah, including one's office. Therefore, even if one will not be at home for Pesah, he must perform Bedikat Hames the night before he leaves. This is done without a Beracha, unless it is done the night before Pesah.
The prevalent custom, according to the Arizal (Rav Yishak Luria of Safed, 1534-1572), is to take ten small pieces of bread (less than a Kezayit), wrap them in foil or paper, so that there will not be any crumbs, and place them around the house to be found. It is best to wrap the bread in paper, as opposed to foil, so that it can be easily burned the next morning. It is highly recommended to record where each piece is placed, so as not to lose it.
Bedikat Hames should be performed using a candle. However, today, homes are more flammable than in previous generations, and using a candle may pose a fire hazard or, conversely, compromise the checking, since a person is hesitant to bring the candle too close to many areas. In such situations, Hacham Ovadia permits using a flashlight. Ideally, one should begin the search with a candle, which is the preferred method, and then switch to using a flashlight.
Many people have the unusual custom of turning off the lights for Bedikat Hames. Apparently, the basis for this is the Gemara' s statement that a candle is ineffective in daylight. However, clearly, even if the house lights are on, the candle is useful in searching in corners and remote places such as under the beds, where the regular light does not reach. If someone lost a watch at home, he does not turn off all the lights and only then begin to search. Therefore, it is proper to keep the lights on and use the candle.
