ELECTRIC LIGHT — LITURGICAL USE. — By precise dispositions of the Sacred Congregation of Rites, electric light is forbidden for liturgical use in worship, but it is permitted to illuminate churches or to adorn them with greater solemnity (decrees nos. 3859 and 4322).
1) On altars only wax candles must be placed, and it is forbidden to place electric candles there (whether alongside wax candles or for groups; decree no. 4097). It is forbidden to place electric candles in front of or around the throne for the exposition of the Blessed Sacrament or inside the ciborium (4275), in front of sacred relics, or before sacred images placed on altars (4206 and 4322). In front of the altar, where the Blessed Sacrament is reserved or where sacred relics are exposed, there must be at least one oil lamp (4334 and 86). During the last two wars (1914–18 and 1939–45), due to the difficulty of procuring oil or wax at a reasonable price or in sufficient quantity, the use of electric lamps was permitted (4334 and 86), with the obligation to return as soon as possible to the centuries-old tradition, which was accomplished by decree of 18 August 1949. This venerable use of wax and oil is based on the symbolic meaning and the character of worship in a visible destruction of the material to be burned (86).
2) Electric light is used for the internal illumination of the church, for adorning paintings or sacred images (outside altars), or for greater solemnity (4206 and 4322). The illumination must be serious and sober (3859). Figures, crowns, inscriptions, monograms, symbols, rays, stars, etc., composed of electric lamps are not permitted (4210 ad 1), especially not in various colors (4322). Hidden light sources are preferred. In cemeteries, electric lamps may be used at the graves of the dead instead of wax candles (4378).