The voice that Christine Daaé hears whenever she lights a candle for her father in Phantom of the Opera is that of a mysterious figure known as the Phantom, or the Opera Ghost. To find the answer, you can refer to the original source material, which is the novel "Le Fantôme de l'Opéra" written by Gaston Leroux in 1910. In the novel, Christine tells her friend Raoul about the voice she hears when she lights a candle at her father's grave. The voice turns out to be that of the Phantom, who becomes infatuated with Christine and eventually leads her into the depths of the Paris Opera House.
