"Awaken the Force of the Wasteland."
Fallout 4 has over a dozen potential companions available, each offering unique perks, an extra body during battle, and the ability to carry some of your extra junk for you. In the event you are riding the Star Wars high of this past week and want to bring along the power of the Force as a companion, equipping a suitable weapon is the first step.
The "Lightsaber Renew" mod by invalidfate allows your character to equip a lightsaber. But that's not all - it also comes with the appropriate sound effects, so you can "swoosh" and "shoom" your way through the Wasteland.
Color choices include red, blue, pink, and green. In the event you want to fully embrace the power of the Dark Side, a Darth Vader Helmet mod is also available.
The YouTube video here explains how to install Lightsaber Renew.