1. Soak corn in cold water for 10 to 15 minutes. Melt butter over medium heat; stir in lime juice, chili powder, and red pepper.
2. Remove corn from water, and gently pull back husks; remove silks. Brush corn with butter mixture. Pull back husks over kernels, twisting tops to secure husks. Grill corn, uncovered, at medium-high 25 to 30 minutes, turning several times to cook evenly on all sides. (The outside of corn husks will be charred.) To serve, pull back husks and tie together with a piece of the husk to form a handle for the corn. Season with sea salt and black pepper; serve hot. Garnish, if desired.