The most extensive list of summer camps is without a doubt to be found under http://www.ticinoperbambini.ch/Colonie-Corsi. Just click on the course and it will give you more details.
Supertata Alessia offers great kids clubs for the little ones: http://kidsklub.ch.
In July special partnership between Kids' Klub and the Montessori school (www.irmamontessori.ch). Programmes will be open to children ages 4-12. For infos and more details: email@example.com
More Sport Kids Week Summer camp in Tenero: http://www.moresport.ch/
Tasis, the American School in Switzerland: http://switzerland.tasis.com/
Check out the TASIS Summer Programs in Lugano and in Chateau d'Oex.
Active English, Lago di Como: http://www.activenglish.it
Scuola Steiner, Origlio: http://www.scuolasteiner.ch/centro-estivo/