When I lived in Boston, in 1983, my driveway was paved by illegals. They had a fleet of trucks, with their name on the side, and an office with their name in the window. They had an ad in the Yellow Pages.
Cash only, of course.
What they did not have were the 57 permits Massachusetts requires to start and run a business, income tax, unemployment tax, Mass Jobs Bank tax, Mass Healthy Start tax, Mass required business insurance, etc, etc, etc.
Paying your taxes and obeying the law is one thing. But when citizens are the only ones who have to do that, it makes much less sense.
What they also did not have, surely, was Workman's Compensation Insurance and Liability Insurance. If one of those workmen strains his back, guess who the attorney is going to look at to pay the bill?
Most of these illegals work as "independent contractors" of the company that hires them. If the homeowner is paying in cash, this money is distributed to the worker directly, and the employer/employee relationship is established between the homeowner and the worker through the payment of this money. The company is just the shell that arranges the work.
When the employee hurts himself, it is the employer, i.e. the homeowner, who is responsible. If the employee was not issued proper safety gear or was working in a dangerous manner, it is the employer, the homeowner, who was negligent. And there is the nice, big, expensive house, just sitting there, to put a lien on to guarantee payment.
Anybody who hires illegals to work on his house should have his head examined. He might save a couple of bucks by paying sub-minimum wage, but he puts his entire property at risk.