Sometimes a spouse is disabled - even in a nursing home, mental facility or rehabilitation center. The question becomes if there are "things to know" regarding how to proceed.
If the issue is your spouse being psychologically disabled & in a mental facility, then you may need to serve him/her via the Mental Hygiene Law. This usually entails an application to the Court to approve service of process on the Director of the facility. The Court may also require you to file an application to have a guardian appointed for your spouse.
Special Needs Trusts
Another thing to consider is division of assets and/or maintenance (i.e., alimony). If your spouse is disabled & his/her living expenses are covered by the government (usually via SSD or Medicare), then you may be best advised to set up a "Special Needs Trust." This is a vehicle allowing for transfer of money and/or assets to your spouse and having same administered by a trustee (who usually chrges a nominal fee). The primary purpose of same is to avoid the government considering that money or assets to be your spouse's - and thus reduce or eliminate their qualification for government benefits.