JACKSONVILLE, Fla. -

Jacksonville City Council President Bill Bishop is one of the latest registered voters to receive a fraudulent letter claiming to be from the Supervisor of Elections. The letter claims he might not be eligible to vote in November.

"I hope they find these guys and throw the book at them," said Bishop. "Because regardless of your politics everyone has an opinion. But when you start you're messing with something really serious."

The letters, written on Supervisor of Elections letterhead and appearing to be from Duval County Supervisor of Elections Jerry Holland, question whether the voter is a U.S citizen. The letters say in order to remain on the voter roll for the November election, a person must return a form with personal information, like their social security number, within 15 days.

DOCUMENT: Fraudulent letter to voters

Both Democratic and Republicans voters have been targeted.

Vicky Oakes, St. Johns County Supervisor of Elections, also issued a statement that the letters were being sent to some voters.  Any St. Johns County resident receiving the letter is asked to call 904-823-2238.

"It is also very important to retain the envelope and all papers so they can be turned over to investigating authorities," Oakes said.

Florida Secretary of State Ken Detzner said there are reports of similar letters being received by voters in 28 counties around the state including Brevard, Broward, Collier, Clay, Escambia, Hillsborough, Indian River, Jackson, Lee, Liberty, Orange, Osceola, Palm Beach, Pinellas, St. Lucie, Seminole, Sumpter and Volusia counties.

"Everyone I've talked to seems to be speculating on a motive about what's going on, and the only thing that seems consistent is that it's some kind of effort to cause mischief and disruption for whatever purpose," said Bishop.

The Florida Department of Law Enforcement and the FBI are working to track down the person, or persons, sending out the letters.

The letters look like they were sent locally, but were actually postmarked in Seattle, Washington. If you have received any of the fraudulent correspondence, Holland said to turn it over to authorities.

"When I first saw it, my first reaction was that it was just another piece of political junk mail," said Bishop. "I was ready to throw it out."

"If it's not a signed letter by your county supervisor of elections, it's not a valid letter. If you get it also and it has a return address from Seattle, Washington but it says it's from the elections office, don't open it. Bring it to us because officials would like to fingerprint the letter." says Holland.

The Florida Division of Elections urges anyone receiving one of the letters to contact its voter fraud hotline at 877-868-3737 or visit Election.dos.state.fl.us.