Real life story: Ron and Barb were in their 70's. Sadly, Ron developed Dementia and was under doctor supervision. Ron was unable to remember important things about his life and could not complete financial paperwork due to this condition. Unfortunately for both of them, they never completed an estate plan, so Ron did not have a Power of Attorney that allowed Barb to make financial transactions for him.
Barb wanted to sell their long-time home and move into a smaller home so she could focus on caring for her husband. She needed Ron to sign the deed for sale, but due to his medical condition, he simply could not. Barb was worried she would have to establish a full-blown conservatorship over her husband, which meant regular court involvement in their private lives as well as yearly fees to maintain the conservatorship. Barb was confident she could otherwise take care of Ron without a conservatorship but needed to complete the sale of their home.
Luckily, California Probate Code sections 3100 et seq. allows a spouse to petition the probate court for authority to enter into a particular transaction for the incapacitated spouse in lieu of a conservatorship. This method works best when the transaction in question covers an community property asset (a joint marital asset). If the court grants the petition, Barb could sell the house by legally signing for Ron. Barb would only have legal authority to sign for Ron for the specific transaction covered by the court order.
There are various complex legal details that must be followed in completing this type of petition, such as proper notice to family members, posting bond and the court's appointment of a Guardian Ad Litem to protect the legal rights of the incapacitate spouse.
There are many probate petitions one could do in pro per; however, I recommend hiring an experienced probate attorney for this one as any delay could be detrimental. And as is often true in these situations, all this could have been avoided if Ron and Barb has set up their estate plan before Ron was diagnosed with Dementia.