Are electric sanctuary candles acceptable?

Canon 940 states only that “a special lamp is to burn continuously before the tabernacle in which the blessed Eucharist is reserved, to indicate and to honor the presence of Christ.” While the traditional lamp with a wax candle is normally used to burn near the tabernacle as a sign of honor shown to the Lord (Holy Communion and Worship of the Eucharist outside Mass 11), the canon does not indicate what type of lamp is required. So, yes, it is permissible to replace the wax candle with an electric lamp.