The housemaid calling in to Radio Guanaquisima's "Comunidad" hour sounded nervous.

"I really need help, but I don't have time to talk about it now," she whispered in rapid-fire Spanish. "I've been here one month. I don't have legal papers. And my boss is abusing me."

The show's featured guest leaned into her microphone at the Rockville station and answered in a soothing tone. "Don't worry. Just call me later, and I will see what I can do," said Silvia Navaf in Spanish. "You can call any time. I even check for messages over the weekend."

A paralegal with the immigrants rights group CASA de Maryland, Navaf has made it her personal mission to rescue Washington area domestic workers from exploitation. And if the response to her appearance on the Spanish-language AM station last week is any indication, there is no shortage of women who need her help.

No sooner had the housemaid hung up than the studio phone rang with another caller -- a nanny who cares for five children and was wondering if she was being paid below Maryland's minimum wage.

"You're supposed to get no less than $5.15 per hour, $7.72 if it's overtime," Navaf replied. "And remember, nobody can force you to work more than 40 hours a week if you don't want to," she added, as the phone began to ring with yet another caller.

Navaf has tried to spread the word about her work by taking out ads in Spanish-language newspapers and by distributing fliers in local parks where nannies take their charges to play.

But she has generated the most attention by taking to the airways on Spanish-language radio stations about every two months.

In the days following a typical appearance, CASA de Maryland gets about 10 calls from women seeking assistance, Navaf said.

Indeed, she had hesitated before going on the radio show last week out of concern that she would be inundated with more clients than she can handle.

CASA -- which receives funds from the state and Montgomery and Prince George's counties, and does not charge for legal services -- has only one lawyer to represent domestic workers, Navaf said.

But she was buoyed by the knowledge that previous outreach efforts have enabled CASA to obtain justice for dozens of workers. Some of these cases involved simple instances of underpayment, cleared up with a single phone call. Others were more dramatic -- as in the case of a Silver Spring couple who forced a Cameroonian teenager to work long hours for three years without pay.

Although exact numbers are not yet available from the census, anecdotal evidence suggests that much of Maryland's domestic work is being done by the area's growing foreign-born population.

Such jobs are often the only option for immigrants who had minimal access to education. But their lack of English skills, unfamiliarity with their rights and, in some cases, illegal immigration status can leave such workers vulnerable to abuse.

On the radio show, Salvadoran hosts Lisette Melendez and Claudia Rodas said the key to preventing such exploitation is to educate immigrant workers about their rights.

But persuading immigrant workers to stand up for themselves is not always easy. One caller, a housekeeper who said she was not compensated for her injuries after she slipped and fell while working, continually noted: "I don't want to take advantage of this situation."

"Getting paid what you are owed is not taking advantage of the situation," Rodas finally interrupted. "If we Latinos keep thinking that way, we'll never achieve anything."