In a medium nonstick skillet, heat butter over medium heat. Add onion and corn. Sauté for 30 seconds; add tomato and jalapeno. Sauté 5 minutes. Stir in chicken, lime juice, cilantro, and salt. Sauté 3 minutes. Remove from skillet; set aside.
Top 4 of the tortillas with equal mixtures of cheese topped with corn mixture. Top with remaining tortillas. Heat skillet coated with cooking spray over medium heat. When hot add tortilla "sandwich" (one by one) and cook until cheese melts (3 minutes). Flip over until both sides are browned. Repeat with remaining tortillas.