My father named my sister his POA but then move out of town for 2 years to California(which he ended up in a nursing home to receive the proper). He wanted to come back home. I flew out and picked him up. I brought my dad back to Illinois. My sister who had POA papers from 2 yrs decided to took him out the nursing home and brought him home. She felt as if she could provide the same care as a nursing home. My father has dementia and limited moblity. He's in the hospital now and i will go back to her home. I feel he is not receiving the proper care, is there any way to change his POA or obtain guardianship?