FRESNO, Calif. (KSEE/KGPE) – A community of Democratic voters in California is on alert after receiving threatening letters apparently targeting people with Harris-Walz signs in their front yard. Democratic voters in Fresno with signs in their front yard supporting Vice President Kamala Harris and Minnesota Gov. Tim Walz received a letter on Oct. 29 that states their homes will be used as a "sanctuary residence" for undocumented migrants. "Somebody drove around our neighborhood, jotted down all of the street addresses that had Harris signs in their yards and sent them this letter," said Carole Laval, a registered Democrat in Fresno who received the letter. "To receive something like this, it's un-American," Laval said. "We're exercising our right to free speech. This is not right." Why doesn’t the popular vote determine the president? The letter, written in English, Spanish, and Arabic and authored by a fictional organization, says folks who leave Harris signs up will have their personal addresses released to migrants for the next four years. "The envelopes are addressed to the DNC and the street address of where the sign is, with the return address being DNC and one of the other addresses on the list," Laval said. Carole and other neighbors contacted the U.S. Postal Service to file a complaint of mail fraud. The FBI and Fresno County Sheriff's Office were also notified of the threats. Nexstar's KSEE/KGPE reached out to law enforcement for comment, but didn't hear back by publication time. One neighbor said she threw away the letter because it didn't look real. Here’s what to do if you lose an absentee ballot before Election Day "I was angry. And it's not deterring me from taking down my signs. I came down here to buy more signs," Michele Richtel, a registered Democrat who received the letter, said. When she realized the letter had her address printed on it, it put her on guard. "I'm not going to bow down to cowards who are trying to intimidate me and keep me from voting. I'm a mother of seven with six daughters and I will not stand for living in the 1700s again That's ridiculous," Richtel said. While California as a state reliably votes blue, the votes tend to be closer in Fresno County. In 2020, President Joe Biden won the county with 53% of the vote to former President Donald Trump's 45%. In 2016 it was even closer: Hillary Clinton earned 49% while Trump got 43%. The rest of the votes went to third-party and write-in candidates. The vice chair of the Fresno County Democrats says they'll do what they can to find whoever sent the letters. "We cannot let people threaten us and take away rights as important as voting, and we will not allow that or stand still for it. We will do everything we can to find out who is doing this and to get them prosecuted to the full extent of the law," Fresno County Democratic Party Vice Chair Marsha Conant said. One neighbor also said that she contacted the Fresno County Sheriff's Office, which said it will conduct more patrols in their community.