Here in UGLE, we have no fixed rule on this. Some of our buildings are equipped with electric bulbs, others are equipped with candles, both are common. I've not seen the S&C lamps referred to in this thread, I don't think we have those over here, but we do sometimes use the slightly flickery imitation-candle bulbs. Where we use actual candles, some places have traditional wax candles, but other places (such as UGLE HQ) have oil-filled (and re-fillable) waxless candles to avoid creating a mess. (Incidentally the positioning of ours is different from yours, we have them at the edges of the room beside the WM and the Ws, so the hypothetical risk of damaging the VSL doesn't apply here.)
The main symbolic point, of course, is that it is a light, and the technology used to produce the light is a secondary issue. Nevertheless, I much prefer candles, which I find maintain a more effectively authentic flavour in the proceedings.
T & F,
Huw