My finch is missing feathers over night? Help?!?

hello, i am soo sorry to hear about your bird, i too had a problem with a bird who looked healthy but was loosing his feathers! (i own a canary) .... do you know if they have mites? because that could be it! if that's the case your avian vet will give him some ivermectin shots (on the skin) and in no time you will have a feathery lil finch :)