I don't like aluminum wiring or knob & tube. 

Getting a home inspection should also help you see if there are problems with the major building systems.Homes built before the 1950s, especially those with balloon framing, knob-and-tube wiring, or galvanized plumbing, often require full guts.

However, it could cost you thousands of dollars for info that you can obtain here on BP and You Tube.

Then they will put drain tube and spillway in.  

They do draw a hard line with cloth wiring, even if it is in good condition and not knob n' tube. 

Hi Steve from El Centro, CA-Congratulations on your wife and yourself being interested in small to medium sized multifamily outside of California.You are trying to educate yourself and asked about what to read and You Tube channels to follow.I like Multi-Family Millions by David Lindahl and Ken McElroy and Peter with Commercial Property Advisors on You Tube.To keep things real simple, I would find a commercial broker that has a teacher's heart that can help you evaluate deals and model out what you would like to do before and after you purchase to increase value.Then, if the commercial broker is any good, they will have referrals to all the other team members you need but a big one is the property manager and you want them involved helping you evaluate deals before you buy and planning with you how to increase value.After that, you want an excellent attorney, lender, insurance agent, and property inspector.There are some great opportunities here in Michigan if that is a market that interests you.To Your Success!

Check out this You Tube channel.

I'm particularly fond of knob n tube, screw shell fuse panels, aluminum wiring, undersized underground services, galvanized plumbing and asbestos HVAC upgrades.

Septic tank, knob and tube wiring, plastered wire mesh walls which I have removed from the studs.

No dishwasher, old appliances, and my unit would need a renovation to be livable long-term.The electrical panel has been upgraded to circuit breakers, but Knob and Tube wiring likely still exists.