There are no digging spots in Six Flags Fun Park (Wii). The game is a collection of 40+ mini-games themed around theme-park attractions (roller coasters, midway games, water rides). Core mechanics are motion-controlled: swinging, tilting, shaking, pointing—no excavation, digging, or treasure-hunting gameplay exists.
If you're stuck on a specific mini-game, describe the ride/game name—I can give control tips.