The search for hametz in one’s house before Passover should be performed by candlelight.

Mishna: On the evening of the fourteenth, one searches for leavened bread with the light of a lamp.

Gemara: The Sages taught: One searches neither by the light of the sun, nor by the light of the moon, nor by the light of a torch with multiple wicks, but rather, by the light of a lamp, because the light of a lamp is effective for searching…. A lamp but not a torch? Rav Nahman bar Yitzhak said: One can put this lamp into holes and crevices, and one cannot put that torch into holes and crevices, as it has a large flame. Rav Zevid said: This lamp projects its light before it, and that torch projects its light behind it. Rav Pappa said: When using this torch, one fears starting a fire, and when using that lamp he does not fear starting a fire. Ravina said: Concerning this lamp, its light is drawn and steady, but the light of that torch is unstable and jumps. (Mishna Pesaĥim 1:1; Pesaĥim 7b)