No one ever lit the candles on the wall sconces. Ever. They were for decoration only, and even if company came over you didn't light them.
If you did light them for a while you would have to throw them away the next day. Lest people think you used your good candles.
We had special candles - they had a twist like the pillars of the altar at St. Peter's, and they matched the sconces. They could never be used. Replacements were presumed not to exist.