In a bowl, combine flour, paprika, garlic powder, onion powder, and cayenne pepper. Season with salt and pepper.
In a separate bowl, soak chicken thighs in buttermilk for at least 15 minutes.
Dredge chicken in flour mixture, ensuring it's fully coated.
Heat vegetable oil in a large skillet over medium-high heat. Fry chicken until golden brown and cooked through (internal temperature of 165°F), about 6-8 minutes per side.
While chicken is frying, grill or boil corn until kernels are tender. Cut kernels off the cob.
In a bowl, mix corn, mayonnaise, sour cream, Cotija cheese, cilantro, and lime juice.
Warm tortillas. Assemble tacos by filling tortillas with fried chicken and street corn mixture.