You know the way that fairy paper cake cases are pleated ? (cupcakes they're called now) There are similar ones made of tinfoil that fit inside candle sconces to make a too narrow candle fit snugly.
You can make them yourself from either tinfoil (if it doesn't need much adjusting) or better yet from patiently folding the thicker foil from the cases that mince or apple pies often come in.
If you can't find the candles to fit, it's worth the footering around with
cheers,
Toddy