PROVIDENCE — A resident of Chichester, N.H., posted a resumé online and received a response about a job offer from a company in the United Kingdom.

She was sent a check for $3,000 to buy $1,000 worth of items to perform her new job, and was told to wire back the extra $2,000 via Western Union.

She did it, and later learned that the $3,000 check was counterfeit.

That’s just one example from an alleged fraud scheme involving about $1.7 million in counterfeit checks and money orders, which a Coventry woman is accused of producing on her computer or forwarding on behalf of an accomplice believed to be in Nigeria.

Nancy Alexander, 66, of Hornbeam Road, was arrested by federal agents yesterday and charged with one count of mail fraud and one count of aggravated identity theft, federal prosecutors said. The scam targeted up to 400 potential victims. The number of actual victims remains undetermined, prosecutors said.

This is not one of those e-mail scams in which a self-proclaimed government official from Nigeria offers you the chance to get a percentage of money that he’s trying to transfer out of the country. “This isn’t the guy who says, ‘I’m the deposed king or the former oil minister of this country or that country,’ ” U.S. Attorney’s Office spokesman Thomas M. Connell said.

But it is another variation on the so-called “419” frauds, which are named for section 419 of the Nigerian criminal code, Connell said. “This is another one that is, in a way, much more prevalent these days,” he said. Prosecutors described it as a “Nigerian-based overpayment scam.”

“The scam only works if you send money back immediately, before the check or money order is determined to be counterfeit,” Connell said. “If something appears too good to be true, it usually is. When enticed by a scam like this, either ignore it, or deposit the check and wait for it to clear.”

In April, Alexander was arrested on state counterfeiting charges, which are separate from the new federal charges.

According to an affidavit supporting yesterday’s charges, Immigration and Customs Enforcement officials at a border screening center intercepted a Federal Express package that contained 119 counterfeit money orders and cashier’s checks totaling $175,280. Authorities determined the package came from Nigeria and was shipped through France.

On April 4, ICE agents and the state police made a “controlled delivery” of the package to Alexander, and then executed a search warrant at her home, which was then on Victory Highway in Coventry. They found check-writing software, blank-check stock, and preprinted shipping labels from Federal Express and the United Parcel Service bearing various names and addresses from across the country, according to the affidavit. And in her bedroom closet, authorities found 11 sealed UPS packages containing 11 counterfeit checks totaling $39,100, plus 39 counterfeit checks, not in envelopes, totaling $129,250, the affidavit said.

“After being advised of her constitutional rights, Alexander told law enforcement officials that she produced counterfeit checks at the request of an online acquaintance named ‘David Smith’ and ‘Alan Gates,’ ” the affidavit said. “Alexander stated that she knew what she was doing was illegal and that she considered herself to be a ‘middleman’ in the operation.”

Connell said the accomplice referred to as David Smith or Alan Gates is believed to be in Nigeria.

According to the affidavit, Alexander said she received e-mails containing payee addresses, check amounts, and counterfeit Federal Express or UPS labels. She said she would then produce counterfeit checks using computer software, print the mailing labels and drop the packages in Federal Express or UPS boxes, according to the affidavit.

“Alexander states that she knew the checks she was producing were counterfeit and that she was doing it for $600 per month, as she had been promised,” the affidavit said.

An analysis of her computer determined that from March 8 to April 3, Alexander had created 291 counterfeit checks totaling nearly $1.6 million, and those checks had 228 payee names, according to the affidavit.

In June, U.S. postal inspectors mailed letters to 67 of the potential victims, and so far, 24 people have responded. One was the Chichester, N.H., resident, who is identified in the affidavit only as “MK.”

Another was a resident of Spokane, Wash — identified only as “KM” — who reported she was contacted via e-mail through her posting with an Internet dating service. “KM stated that she spoke with ‘Wilson’ who eventually convinced her to deposit a $5,000 check and wire that same amount via Western Union to help him while he did not have access to his other business accounts,” the affidavit said.

But Wilson’s $5,000 check turned out to be counterfeit, and it listed a University of Hawaii account “which is consistent with” Alexander’s software logs, the affidavit said.

Another woman, identified as “KH,” reported that she tried to sell a pool heater by placing an ad in unnamed newspaper and was contacted by a potential buyer. The woman, whose hometown is not given in the affidavit, said she received a check for an amount higher than the asking price, and an e-mail instructed her to wire the difference via Western Union to the “shipping company.”

But “KH” waited until the bank cleared the check, and it turned out to be counterfeit. “After e-mailing that information to the ‘buyer,’ she was harassed and eventually threatened, being told to ‘watch [her] back’ via e-mail,” the affidavit said.

Many of the counterfeit checks were purported to be Bank of America checks from the account of a Lebanon, Ohio, resident identified only as “TC.” According to the affidavit, TC has a Bank of America account that differs by one digit from the number on the counterfeit checks. She told authorities she doesn’t know Alexander or any of the payees.

Connell said none of the known victims of the scheme are from Rhode Island.

Alexander appeared in U.S. District Court yesterday before Magistrate Judge Lincoln D. Almond, who released her on unsecured bond pending further proceedings. No plea was entered. Mary S. McElroy, an assistant federal defender representing Alexander, declined to comment.

efitzpat@projo.com