In the ride they use two thin wires to carry the power down to the candles, which also serve as the suspension and most theme parks' required two-point safety attachment. You could buy the candles with the built in timer which come on at dusk, stay on for 5-6 hours then stay off til dusk the next day. Set it and forget it. If you have light enough candles, you could use magic thread to suspend them, which is nearly invisible. Same thing used on the floating wand effect in hogsmeade.