Everyone throws those slick campaign mailers in the trash. But, handwritten postcards will get a second look and are a personal way to contact voters. You can volunteer with these groups to write cards for candidates that they endorse.
POSTCARDS TO VOTERS
You can also contact a campaign directly and talk with them about writing postcards for their candidate. They can provide information on messaging, addresses, and anything else you might need to know.
NOTE: If you write for a specific candidate then make sure your cards are FEC compliant.