The Kindness Rocks Project is a art/service project that would fit right if your unit has been working on challenges like Be You or Mighty Minds. It is also a really simple and lovely idea. Take rocks, paint them and write inspiring messages on them. Then place them back outside where someone who needs to hear that message might come across them.
The project organizers ask that you Instagram photos of your rocks once you have completed them with the haste tag #TheKindnessRocksProject so that you may inspire other people to join the project.