To prepare: Brush sweet pepper, squash, and onion with oil. Grill sweet pepper in a grill wok, grill basket, or on a greased grilling tray on an uncovered grill directly over medium-hot coals for 3 minutes.
Add squash and onion to grill. Grill vegetables for 5-8 minutes more or until crisp-tender, turning occasionally.
Remove vegetables from grill as they are done; set aside and keep warm. If desired, warm tortillas on the grill for 1-2 minutes.
Assemble wraps: Spread 1 side of each tortilla with ranch dressing. Arrange turkey on top of dressing. Top with slices of cheese. Spoon one-third of the grilled vegetables over cheese just below center of each tortilla. Top vegetables with snipped cilantro.
Fold bottom third of tortillas partially over the vegetables. Fold in sides. Roll tortilla up tightly. Cut wraps into thirds.