Without defining the amount of cash we have, exactly (let's say it is less than $400K, more than $150K), but with defining our current goal as to supplement upcoming retirement income (somewhere in the meager to modest range) what do folks recommend as a good financial strategy to pursue?

I wonder if he's mentioning the supplemental home warranty services? 

I have now been retired from my first profession as an orthodontist for 15 years, am 85 yrs. old and have become somewhat bored with retirement. i have been entirely responsible for the investment of my money in an IRA, but last year was a downer as far as the stock market goes, and I am  starting to get low on money and would like to supplement my retirement income. 

I've done a lot of the work on both of the houses I own, and really enjoy doing it, learning new things about renovations, and improving/polishing my skills.Once I reach my 10 years, I'm contemplating converting a large van into an RV and touring the Americas, probably obtaining certification as an EMT to get some supplemental income and to find adventure.Exploring real estate opportunities in DC, looking for buy-and-hold rentals.

So maybe just a n00b from an investing standpoint.I am exploring Real Estate investment to supplement income and to generate passive income.

After taxes/insurance I'm profiting about $7500 a year from this property.My mom is a successful investor and it has always been a supplemental income for me.

Long story short, home built in the mid 70's -- built VERY WELL -- same owner since around 85 or so -- this owner kept cash out refi'ng over the years to supplement their lifestyle - last mortgage they took out was around 2007, then I'm guessing based on conversations with the neighbors stopped paying the mortgage around 2012 or so if I had to guess.  

I'm most interested in building a source of cash flow and income that 20 years from now can supplement my retirement savings.

If your future is with your degree and you just want REI to supplement your income or offer extra cash for whatever your needs, then I say go and get your grad degree right away.  

The goal is to have a positive cash flow to supplement retirement.