Preheat oven to 325 degrees F.
In a medium bowl cream together the cream cheese and the sour cream. Stir in 1/2 cup of the salsa. Stir in 1 cup of the grated cheese. In a second bowl toss together the chicken, the corn, cumin, cayenne, salt, pepper, and 1/2 of the scallions. Add the chicken mixture to the cheese mixture and stir to combine.
In a baking dish spread a 1/2 cup of the salsa over the bottom. Place about a 1/3 cup of the filling on a corn tortilla, roll up and transfer to the baking dish with the seam side down. Repeat process for remaining tortillas. Pour remaining salsa over enchiladas, spreading to coat all of them. Sprinkle remaining grated cheese over the top. Enchiladas may be prepared up to this point 12 hours in advance. Transfer to preheated oven and bake for 20 to 25 minutes until hot and bubbly. Enchiladas may be reheated, covered with aluminum foil, before service. Sprinkle with the remaining scallions and serve warm.