Remove tough outer leaves of husks and discard. Pull remaining husks back over the stem end, remove silk plus 2 inner husk leaves and cut corn cob off, leaving husks and stem end attached.
Cut corn off cobs. From the inner husk leaves, cut 8 thin strips. Set aside for tying the husks.
Preheat oven to 400° F. Heat oil in skillet over medium heat. Add onion, red pepper and sweet potato; cook until just tender, about 8 minutes. Stir in corn, sage, salt and hot pepper sauce. Cook 2 minutes, stirring constantly. Stir in cilantro; remove from heat. Let cool.
Spoon 1 cup vegetable mixture inside each husk.
Using 2 strips of husk or kitchen twine, tie husks to enclose filling.
Trim excess husk 1/2-3/4-inch from ties. Place husks in a 13- x 9-inch baking pan; bake until heated through about 20 minutes.