Put frozen chicken breasts in the bottom of your slow cooker.
Pour the whole bottle of buffalo sauce over chicken breasts and sprinkle ranch packet on top. Cook on low 6-7 hours. Using two forks, shred the chicken and return it to the crock pot.
Add butter, stir and cook on low for an additional hour.
Serve on buns and serve with a side of ranch dressing.
Notes
If you're looking to tone down the spice try adding sour cream or cream cheese to the chicken after it's cooked.