In a large bowl, combine the chicken cubes, BBQ sauce, olive oil, garlic powder, onion powder, smoked paprika, salt, and pepper. Toss until the chicken is well coated. Cover and marinate in the refrigerator for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill or grill pan over medium-high heat. Thread the marinated chicken onto skewers, leaving a little space between each piece.
Grill the chicken skewers for about 10-12 minutes, turning occasionally, until the chicken is cooked through and has nice grill marks. The internal temperature should reach 165°F.
While the chicken is grilling, prepare the salad by combining the mixed greens, cherry tomatoes, cucumber, red onion, cheddar cheese, and corn in a large bowl.
Once the chicken skewers are done, remove them from the grill and let them rest for a few minutes.
To serve, place a generous portion of the salad on each plate, top with a couple of chicken skewers, and drizzle with extra BBQ sauce. Add diced avocado on top.