Prepare a charcoal grill with a single layer of hot coals.
Peel back the husk from the corn and remove the silk. Brush the kernels with the melted butter and replace the husk to cover the ear of corn.
Grill the corn for a total of 20 minutes, turning it every 5 minutes. Remove the ear from the grill and carefully peel back the husk. Sprinkle the kernels with salt and serve.