Preheat the oven to 350 degrees F (175 degrees C). Grease a casserole dish. Combine cream cheese and butter in a microwave-safe bowl and heat until melted, 1 to 2 minutes. Pour into a large skillet and add milk and flour. Cook, stirring occasionally, over medium heat until mixture thickens, 3 to 5 minutes. Combine corn and jalapeno peppers in a bowl; add to cream cheese sauce. Season with salt and mix well. Pour into the prepared casserole dish. Bake in the preheated oven until lightly browned, about 30 minutes.