In general, updated with clean and modern furnishings is always a good start. 

Or we are all wrong and modern economic theory is flawed and no longer applies...

When I lived in Southern California I worked at a firm that designed ultra modern homes in Hollywood, Beverly Hills, Malibu and so on for a homes that sold between the low price of $10 to $50 million dollars.

We have a lockbox nearby for the tenants if they get locked out but it's 2021, I hoping there is a more "modern" solution. 

You may not know the difference of the great area but look at the photos, and try to stick with: kitchen is modern, has heat and air conditioning.More time consuming but also free: call a couple property managers in given city; US census detailsPaying: rentometer; rentguide; insurify; 

If they have served their time, their debt to society has been paid and you have no right to hold it against them - is the argument that is winning large settlements. 

That's 19 months and counting that housing providers are REQUIRED to work without compensation.And unemployment is at an all time high because it's more financially savvy for folks to stay home and collect the buffed up unemployment than it is to *gasp* re-enter the workforce and contribute back to society. 

For hands off if you want a more traditional broker than Vanguard or for a modern one M1 Finance.

You may have old sewer lines, old wiring, asbestos, lead paint, rubble foundations and various things that fall short of modern code.

If it's Milwaukee, I'd recommend connecting with Sahara Ali at Rethought Realty, Daniel Balderas/Modern Milwaukey, Nicole & MIke Borowski/Homestead Realty and Jodi Graf/Premier Point Realty (Premier Point is a brokerage of investor agents and also Nicole Bruckner specializes in short sales).