In a large skillet, cook the bacon over medium heat, turning often, until half-cooked, about 3 minutes. Transfer to a paper-towel-lined dish. Add the onion, celery and bell pepper to the skillet and cook until softened, about 3 minutes. Stir in the shrimp and cook until opaque, about 2 minutes. Stir in the cornbread; season with salt and pepper.
Cut a 2-inch-wide slit through the center of each chicken breast, beginning from the thicker side and cutting horizontally toward the center to make a pocket. Fill each with one-quarter of the stuffing; press the opening to seal.
Place 2 strips of bacon on a work surface. Lay a chicken breast crosswise on the strips and wrap the bacon around the breast; secure with toothpicks.
Wipe out the skillet and heat over medium heat. Add the wrapped chicken and cook for 3 minutes. Turn the chicken, cover the pan with a lid and cook, turning once or twice, until the bacon is crisp and the chicken is just cooked through, about 5 minutes.