Remove the husk from the corn and place them directly onto the hot grill. Cover, but turn your corn occasionally.
Cook for about 10 minutes or until lightly charred. Remove and let corn cool enough until it can be handled. When ready, cut the kernels from each ear of corn.
Slice bread into 8 slices. Butter each slice with 1/2 teaspoon of butter.
Heat a grill pan over medium heat. Place 4 slices of bread, buttered side down onto hot pan. Arrange 4 slices of Pepper Jack cheese on the bread.
Divide avocado and corn evenly over cheese and top with remaining bread slice, buttered side up.