It is a marriage of convenience she is from Thailand she has her permanent residency, we have put our dad in a nursing home and she doesn’t want anything to do with him now ,we can even get bank details from her to to him in permanent care what can we do .
If your Dad doesn't have a PoA, but still has legal capacity he needs to assign you. If he no longer had capacity, then you may need to go directly to a judge to petition for guardianship. Hopefully the wife is not his PoA... then you may be in trouble...
Otherwise, if his name is not on the bank account jointly, he may need to file for divorce, but not sure how possible this is if he is cognitively impaired.
I agree, you should talk to an attorney in this scenario -- but hurry.
If there is no POA, then wife is next of kin. Her lack of cooperation will weigh quite heavily on the assets of the marriage. And if she makes attempts to trounce on off with the marital assets it may help if you tell her that being jailed for elder abuse in this country is no joke and she may face immigration lawyers soon.
You will need, likely, eventually to see an Elder Law Attorney. You will there find out options and direction. BUT.............
You may first wish to try a call to Adult Protective Services. They may help you speak with the wife; she could be accused of abuse of an elder if she is hiding assets and such. You may get less costly direction and options from the APS than from an attorney, and it's worth a try certainly.
I am quite surprised that you "got" your father into ECF, even temporarily without having POA. The wife would be his next of kin. While there, of course, he will be accumulating debt. The bills will go to him; the wife will be responsible that they are being paid; judgement will eventually go to the courts, a home and his assets, her assets as well.
If the wife fully understands all this she may become more cooperative, esp. if she understands the daily costs accumulating, fears the law and deportation at all, or fears being jailed on charges of fraud and elder abuse.
Best of luck.