No such thing as a sure investment
In 1965, Jeanne Calment, a 90 year old French lady who had no heirs signed a contract of such kind with a 46 year old lawyer. He would get her house after her death, and in the meanwhile he would give her an amount of 2,500 francs monthly.
Even if she lived to be 100, getting that house was still a very nice deal and sure investment.
Except she lived a little longer. She lived to be 122 years, and had the longest (confirmed) lifespan of a human. The contract lasted for 32 years, she actually outlived the lawyer who died of cancer at 77, and his wife continued paying the 2,500 francs until the end, amounting to over $180,000, a lot more than what the house was worth.
Most of us are aware of a system that is in place in many parts of the world, where an old person with no family or relatives will employ someone for help or nursing until they die and then leave them their house as compensation.