There’s no free lunch for these seniors.

Fraudsters are eating them up — and as more older Americans struggle to eke out income and pay bills in this low-interest-rate, lukewarm economy, they’re more vulnerable to the latest scams and get-rich-quick schemes, according to anti-fraud groups.

Law enforcement agencies, fearful of wholesale scamming as the ranks of older Americans explode, are stepping up policing and closely monitoring the trends.

Rick Miles, 68, wishes he had spotted the red flags earlier. A former stockbroker and portfolio manager during the glory years at E.F. Hutton, Miles says he was swindled out of an estimated $500,000 in a scheme involving a New York Stock Exchange-listed company.

“Five years later, there was finally a settlement. I received a check for $2,100,” said Miles, shuddering still at how he, a sophisticated financial professional, was taken to the cleaners.

“It literally destroyed my marriage,” Miles said.

Today, Miles, an associate at the Association of Mature American Citizens (AMAC), conducts workshops for seniors on how to avoid financial fraud. He counted at least 20 seniors in one workshop who had been swindled by cons in amounts from $25,000 to $50,000 each. “It brings tears to your eyes,” Miles said.

About 10,000 Americans will turn 65 each day for the next 15 years — that’s about 80 million by 2040. US life expectancy has soared, and today a senior age 75 is considered “young.”

Seniors are being picked off by every trick in the book, from Bernie Madoff-type Ponzi schemes and toxic alternative investments to old-fashioned penny-stock and pump-and-dump fraud.

Tricks are also being played in shady telemarketing and social-media campaigns — and in online advertising promising the sun, moon and stars to naïve seniors and retirees hungry for the yield they thought they could rely on years ago.

As an example, regulators cite the case of eight people charged with duping thousands of investors of $290 million by telling them to buy penny stocks only to watch their investment disappear, when the promoters dump their shares on the price rise.

The case was brought by Manhattan District Attorney Cyrus Vance in 2014. All parties have pled not guilty.

The Financial Industry Regulatory Authority (Finra) is also in hot pursuit.

“I encourage seniors to come forward and let authorities deal with the conduct because people shouldn’t be taken advantage of,” Susan Axelrod, Finra’s head of regulatory operations, said.

“If something seems too good to be true, it probably is — ask questions, keep documentation and search out the person who solicited you, on our BrokerCheck,” she added, referring to Finra’s online broker background search tool.

Axelrod was speaking after the launch of a new toll-free Finra helpline for seniors — (844) 574-3577 — aimed in part at responding to their complaints about how their brokerage accounts are handled. After just over a week, it had received 130 calls.

“As we all know, there is no such thing as a free lunch,” Axelrod said. “Seniors should be on notice that when they are invited to something, even a free dinner with a free book, someone is trying to sell them something. And when high-pressure sales tactics are used, that should be a red flag.”