Cut the candle from 6 mm thick milky acrylic. Best using a laser cuter machine at a school or a FabLab near you. Buy an LED and a CR2032 (or CR2020) coin battery. Bend the two legs of the LED together and put the battery in between with the longer leg to the (+) side of the battery (like for the LED-Throwies you find on the internet). Then insert to the LED with the battery into the candle. The round piece cut out for the batterie can be used as as stand, just insert it at the bottom of the candle.