Just add this lines to concrete/helpers/lists/ListsStatesProvincesHelper.php

'CH' => array(
'AG' => 'Aargau',
'AR' => 'Appenzell Ausserrhoden',
'AL' => 'Appenzell Innerrhoden',
'BL' => 'Basel Land',
'BS' => 'Basel Stadt',
'BE' => 'Bern',
'FR' => 'Freiburg',
'GE' => 'Genf',
'GL' => 'Glarus',
'GR' => 'Graubünden',
'JU' => 'Jura',
'LU' => 'Luzern',
'NE' => 'Neuenburg',
'NW' => 'Nidwalden',
'OW' => 'Obwalden',
'SH' => 'Schaffhausen',
'SZ' => 'Schwyz',
'SG' => 'St. Gallen',
'SO' => 'Solothurn',
'TI' => 'Tessin',
'TG' => 'Thurgau',
'UR' => 'Uri',
'VD' => 'Waadt',
'VS' => 'Wallis',
'ZG' => 'Zug',
'ZH' => 'Zürich'
),