We already have torches, two block tall tiki torches and chandeliers, it would be nice to be able to make candles out of some form of wax, maybe add some tree sap you can get from pine trees that you can turn into this type of wax, or some bees (we can steal the sound from midges for bees if anything)
Reasons candles would be cool is it would add to the aesthetic players would like, you can also change up the texture on the chandeliers to have candles if they are crafted with candles.
Please consider this, it would be really cool to have candles in the game.