Medicaid seizing house?

You need to check for yourself. No, Medicaid will not seize the home. However, when your Aunt dies Medicaid will recover what costs they are able, that they provided for her care, when the home is sold. That is to say that medicaid will have a lien on this home. This is speaking of course in terms of a primary home. If there are income properties they are considered assets that should be spent down before applying for governmental assistance.
Medicaid is a joint program with state funds, and rules differ state to state. You would be wise to seek the assistance of an elder care attorney to have questions such as this answered for your own area. You cannot afford to make mistakes by taking advice from people on a Forum. There are a few here who are very informed about these things, but legal and medical matters require your own expertise sought in your own area of the country.
I agree with Joann that the best thing to do might have been to sell the home and use the assets to keep the Aunt in her ALF, which is often very preferable over nursing home.

No...Medicaid will not take the home. Its an exempt asset. But your Aunts SS and any pension will be needed to be used to offset her care. That means there will be no money to pay taxes, utilities and up keep on her home. Medicaid does determine who is allowed to live there. It can't be rented without their knowledge. A Community spouse can remain but others need to show why they should be allowed to stay there and if they can pay for everything associated with the house.

Why was the house not sold to pay for her care in the AL? She could have remained longer. If u hold onto it, someone will need to pay the bills until her death. Then, Medicaid will put a lien on the house because the house is no longer exempt. If someone is living in the house again they have to show a reason they should be allowed to stay. If Medicaid does not except someone being allowed to stay in the home, it needs to be sold so Medicaid can get recover the money they spent on the person's care.

a lien will be placed on the house. after she passes medicaid will determine the amount that was spent on her care. Medicaid estate will try to recover their funds, but no more than that.