For marinade, in a bowl or in a plastic bag set in a bowl, combine olive oil, chili sauce, tequila, garlic, salt, and red pepper. Rinse shrimp; pat dry. Add to marinade. Cover; marinate in refrigerator for at least 2 hours or up to 6 hours, stirring occasionally.
Spray the rack of an uncovered grill with cooking spray before lighting coals. Drain shrimp, discarding marinade. Thread shrimp onto eight 10- to 12-inch metal skewers, allowing 1/4 inch between each.
Grill the shrimp over medium-hot coals* for 6 to 8 minutes or until the shrimp become opaque, turning once. Makes 8 servings.
To test for medium-hot heat, you should be able to hold your hand over the heat at food height for 3 seconds before having to pull away.