Undercover investigators took us through one house in need of major repairs.
"Carpeting needs to be repaired, floors sanded, re-surfaced," one investigator told us.
Twenty home improvement contractors were called to this home, all asked for estimates.
"They came in and they really couldn't care less about the story," said another investigator. "It was all about money."
And at least HALF of them didn't have the required home improvement registration to operate in the Garden State!
"If they're not registered, these consumers often have no recourse if that home improvement contractor doesn't follow through on what they said they were going to do," said Eric Kanefsky of the state's Office of Consumer Affairs.
As a result of the sting here, ten unregistered contractors were cited, including Get it Done Painting of Trenton, NE Home Improvements of Philadelphia and Tara Construction of Lawrenceville.
"We fine them, we penalize them, we take them to court if they're not willing to pay those fines," said Kanefsky.
These contractors could also be criminally charged.
"One of the leading complaints we get is about home improvement contractors, people who are performing sub-standard work, giving fraudulent quotes, or trying to rip people off - aren't finishing the job," Eric Kanefsky told us.
"And I assure you, when we do things like this," he continued, referring to the sting operation, "word spreads pretty quickly to people who are out there and are not registered. Hey, you need to get registered, you need to get insurance, you've got to do it the right way."
To protect yourself from a potentially bad contractor, you need to do a minimum of two things.
First, get the contractor's home improvement registration number. It should be clearly marked on the company truck and contract.
And second, call the Division of Consumer Affairs or go online to get the contractor's complaint history, insurance information and more.
New Jersey even has a Professional License Lookup app for your smart phone.
And remember, Pennsylvania home improvement contractors must also be registered.