Non-working spouse of a posted worker
You accompany your employed spouse, who continues to be insured in Switzerland, to live abroad and are not employed there. You can join the compulsory insurance scheme.
In case of employment abroad and place of residence outside the EU/EFTA, you can join the voluntary insurance scheme, provided that you comply with conditions.
More useful information is available here:
Leaflet 10.02 - The voluntary old-age, survivors' and disability insurance scheme (pages 23-29)
Leaflet 10.03- Citizens of States with which Switzerland has not concluded an Agreement on Social Security (pages 41 to 52).