Combine salt and ground chiles on a small plate. Rub the rim of a chilled 12-oz. glass with lime wedge, then dip in salt mixture.
Fill a cocktail shaker three-quarters full with ice. Add lime juice, tequila, Bloody Mary mix, and hot sauce and shake until cold. Pour ice mixture into glass and garnish with whole chile. For a thinner cocktail, let it sit on ice about 5 minutes.
*Find arbol chiles at Latino markets. Grind about 2 minutes in a clean spice grinder.