A christmas tree consisting of two parts.

Inside the trunk there is room for two AAA batteries. Internally at the top there is space to put a 5mm LED. Light is shed downwards through the branches.

In part 1 there is a 1.5mm slot within the trunk next to the batteries to lead the ground wire to the upper part of the tree. The wire can be led through two small holes to a 12mm hole just underneath the branches where a switch can be placed.

For a christmas tree with a light you should print part 1 at least once (and either part 1 or part 2 can be used to make up the whole tree).
If you want just a tree without any elecronics it is nicer to print part 2 twice.

You can use double sided tape to stick the parts together. This allows you to change batteries after a while.