Heat oil in a large, non-stick skillet over medium-high heat. Add the shrimp, garlic and shallots. Season with chile powder and salt and stir. Sauté until shrimp are pink and almost cooked through. Squeeze the juice of half of the lime over the shrimp, add tequila and stir. Let the shrimp finish cooking and remove from heat.

To serve, place shrimp on a double layer of warmed tortillas. Top with avocado, cilantro and radishes. Squeeze a lime wedge over each taco before digging in, if desired.