They could present a danger to you and your family.
State regulators say unlicensed contractors present a great risk.
A home on Bronough Street in Tallahassee was the site of a recent sting operation.
Florida's Department of Business and Professional Regulation lured unlicensed contractors to the home with the promise of construction and electrical work.
"Any time a house is not structurally sound or the electric work is not done correctly, there's obviously some safety risks involved," said DBPR Spokeswoman Beth Frady.
One of people who showed up at the sting home was 59 year old Vincent Peck.
State records say Peck offered to re-locate and upgrade the electical box for roughly $1600.
Once he made the offer, regulators says Peck broke state law because he's not licensed to perform that service.
When reached by phone, Peck told us he's a master electrician who recently returned to the field and didn't realize the rules had changed.
He says he's working with the state to get his license up to date.
"The department's ultimate goal is compliance with the law," Frady said.
The sting caught 6 other men.
Regulators say one of them, 51 year old Joe Wunsch has been caught for a second time.
He's been fined $1000 for advertising plumbing and electical work without a license.
Wunsch told us by phone he's a painter only and didn't know about the fine.
"If an unlicensed contractor does work on your house and it turns out to be shoddy work, your insurance won't cover that," said Frady.
By contrast, licensed contractors must pass tests and have continuing education.
The cease and desist orders from the sting were all forwarded to the state attorney's office for possible criminal prosecution.