Rune Switches are one of the many collectibles you can find sprinkled throughout the Wonderlands. These collectibles require you to activate a pedestal that sends out three rune-covered objects to a nearby area. You will then hear a ticking. During this time, you need to figure out where the objects went and how to reach them. After interacting with all three of them, you get a nice reward of a small loot pile. Almost every area has one of these collectibles. Here is where you find the Rune Switch in Wargtooth Shallows in Tiny Tina’s Wonderlands.
Wargtooth Shallows is the area you go to after completing the Emotion of the Ocean quest and unlocking the Nocean area of the Overworld. Before you can reach this area, you will need to deal with the kelp that is blocking your path. This is done by completing the Miracle Growth quest that you get from the alchemist in front of the entrance to Wargtooth Shallows.
Once you get into Wargrooth Shallows, Follow the path forward until it splits. Stick to the right and go to the right each time the path splits. You will eventually find yourself in a cave. If you are doing the Ballad of Bones quest, you will automatically come to this cave when in search of the First Mate. Exit the cave from the other side of where you came in, and you will find the Rune Switch next to a jump pad. Upon activation, all of the relics will teleport to the area in front of you. Take the jump pad over and follow the path up. Each relics is along the main path and is easy to grab.