Remove the husks and silk from the corn and cut the kernels from the cobs.
Add the corn to a large mixing bowl.
Add the all-purpose flour, rice flour, baking powder, salt, black pepper, cayenne, feta, beaten egg, and ½ cup milk.
Stir until a thick, scoopable batter forms.
Keep the additional ¼ cup milk nearby and add only if needed to loosen your tested batter.
Heat the neutral oil in a deep skillet to your tested frying temperature.
Cook one small test fritter first.
Scoop portions of batter carefully into the hot oil.
Fry in batches until the first side is golden and firm.
Turn carefully and continue frying until both sides are crisp and deeply golden.
Transfer to a rack or paper towel to drain.
Serve hot.