WARNING! Joining in the refinancing of a home previously owned by your spouse or significant other does not guarantee that you actually “own” part of the house.
Husband and Wife #2 evaluate their joint financial situation. They decide that it would be financially helpful to them if they were to refinance the home that they live in. They apply for, and are granted a new mortgage. It is at a better interest rate, especially since Wife #2 is a co-borrower. Husband and Wife #2 both sign the refinance agreement, but there is no deed filed in the county records which gives part ownership of the home to Wife #2.
The couple goes along happily with their life. Then, Husband dies suddenly, and without a will.
It is very unlikely that the Husband in the example wanted this to happen. It is more likely that he wanted Wife #2 to own 100% of the house upon his death.
Secondly, the Husband could have had a valid will, which would have spelled out exactly what was to be done with his 50% upon his death.