Another great way to earn some hard tax-free cash is "Farmer's Market"... Check with your state first
The state where I'm from support tax free farmer's market - meaning whatever you earned at these places, you don't need to report it and it's all cash.
Yes, it's hard work but average people can pull in $2-3G per weekend. The only bad thing is that it's only opened from April to Oct.
I know a few retired Hmong that does where I live.
I don't have time to do it and not married... but if I was, I would probably have my wife do it and I'll just help her out after work or on the weekend.