The Solution:
1. Head back to the entrance of the gym. You'll find a hidden switch near the entrance, usually hidden behind a small rock or some foliage.
2. Interact with the switch. This will deactivate the electric fence, allowing you to leave the gym.
Where to Find the Switch:
* Precise Location: The exact location of the switch might vary depending on your ROM version or patch. Look closely around the gym entrance, especially near any small obstacles or in corners.
* Use Your Eyes: The switch will be a small, usually glowing object. It might be easy to miss at first!
Tips:
* Use your Pokemon's Detect: This ability can help you spot the switch more easily.
* Check Online: If you're still having trouble, search online for specific guides for your version of Light Platinum. They often have detailed instructions with screenshots.
Good luck! It's a bit of a tricky obstacle, but once you find the switch, you'll be free to continue your adventure.