There are four ways for a company not resident in Switzerland to "employ" someone residing in Switzerland:
1) Self-employed: Your husband is registered as self-employed in Switzerland and could agree a contract with your husband's current company as a contractor.
- In theory, this would not work for the situation described because he would only have only customer. As a practical matter, it is possible that the SVA might turn a blind eye if it doesn't go on too long.
2) Incorporated entity: Your husband incorporates a legal entity such as a GmbH/ LLC, of which he is an employee. The legal entity, owned by your husband, would then sign a contract with your husband's current company.
3) ANOBAG: This is where your husband, resident in Switzerland, is an employee of the company. The employee would be responsible for social security payments on the company's behalf, which could also be outsourced to an accounting firm.
4) Payroll Service: This is where your husband's company would contract with a payroll company such as Adecco, Randstad, etc. which would hire your husband under contract to your husband's current employer.

Based on what you described, 3) and 4) would be most practical and risk-free. 1) might work but would entail risk, imo.

Hope this assists you.