What is the ruling on the custom of the mothers of the bride and groom carrying special candles and dancing with them in front of the bride at weddings, and what is the ruling on manufacturing and selling these candles?

It is permissible to show joy and happiness, and there is no harm in welcoming the bride with lit candles and dancing, as long as it is not intended as an act of worship or imitation of disbelievers. A woman dancing in front of other women is permissible if she covers her 'awrah. It is also permissible to manufacture and sell these candles as long as they are used for permissible purposes.