Artificial candles used in the theatre appear completely realistic, down to the flicker of the flame. They work on small batteries which are placed in the base of the candle.

These candles relieve the actor from worrying whether a candle will ignite or not.  It is also a safer medium on stage, and in some countries, where lighting a fire on stage is not permitted, this is the only way to achieve the effect of a flickering, shimmering candle flame.