1In small bowl, mix ranch dressing and avocado.
2Spread 1 side of each bread slice with butter. On work surface, place 6 bread slices butter sides down; top with turkey, bacon, tomato, cheese and dressing mixture. Top with remaining bread slices, butter sides up.
3In 12-inch skillet, place sandwiches. Cover and cook over medium heat 4 to 5 minutes, turning once, until bread is crisp and cheese is melted.