Writing postcards for a cause or a candidate is a great excuse for a small event–or a reason to get-together regularly!  You can contact a local candidate to see if they have a system, or use one of these pre-planned programs.

The first link is to the program itself and there are many links at that site to places to order postcards.  The 2nd link is an etsy account to choose postcard designs.

https://postcardstovoters.org/volunteer/

https://www.etsy.com/listing/604425699/exclusive-100-card-set-for?ref=shop_home_feat_2