I am told Adult Protective Services can help in some way? 

I am sure I have a ton more, as I've been in the same ~2000 sf house for 25 years that used to have 2 kids along with us 2 adults, and the house has always felt like it had more room than we needed.

After the purchase, I found out that one of the adult sons of the previous owner has been living there since his dad died.

She's an adult who signed a contract and, presumably, knows how to use the internet.

I believe the DC area is #2 among cities with adult roommates next to San Fran so this may not apply to a lot of people.

Four adult joint tenants.

I'm looking at a property now that has been mis-managed by some adult siblings, who received the building after their parents' death several years ago.

Local examples I've witnessed result in selling the house (and evicting kids / grandkids), because young adults saddled with student loans, wage stagnation and transient employment have do not afford many the option to buy.

I have been self employed for most of my adult life.

Stick to the basic luxuries, an HDTV with a Roku and a BluRay player with some adult movies.