Christmas lights are not mere decoration. You install them to ward off holiday elves. From the end of November and throughout the month of December, these thieving elves break into your home and steal all manner of things. Setting up Christmas lights is like leaving your outdoor lights on when you travel for work or vacation. It fools burglars into believing someone is home, forcing them to steal from another house.
You might find yourself wondering who these elves are and only do their burgling at this particular time of year. Well... let's just say that if you have a manufacturing facility ("workshop") and you give your products away for free, then you've got to get the cost of your raw materials as low as possible.