1. Combine first 5 ingredients in a large bowl.
2. Stir together squash and next 3 ingredients; add to cornmeal mixture, stirring until blended.
3. Pour oil to a depth of 1/2 inch into a deep cast-iron skillet; heat to 350°.
4. Drop batter by tablespoonfuls, in batches, into oil; fry 3 minutes on each side or until golden brown.
5. Drain on paper towels; sprinkle evenly with 1/2 teaspoon salt.