Place the buffalo sauce, water, ranch dressing mix, and chicken in a slow cooker. Cover, set to low, and cook for 5 hours.

When the chicken is done, shred it with two forks inside the slow cooker. Add the butter and stir.

To assemble the wraps, spread the mayonnaise over the tortillas, layer the chicken, lettuce, tomato, cheese, and avocado. Fold in the lower end of the wrap, then fold in both sides and roll up. Cut each wrap in half before serving.