In a skillet, cook the onion and the bell peppers in the butter over moderately low heat, stirring, for 3 minutes, or until the vegetables are softened. While the pepper mixture is cooking, cut the corn kernels off the cobs with a sharp knife. Add the corn to the skillet and cook the mixture, stirring, for 2 minutes. Add the wine and salt and pepper to taste and simmer the mixture, covered, for 5 minutes.