Q:

Internship in Switzerland after French student visa

I am a US student studying in Paris for the spring semester. I am in the process of getting my student visa, which will be valid until mid-July. 
However, I am planning to intern in Switzerland until mid-August. Once I leave France, am I able to stay in Switzerland? and for how long? Or must I leave the Schengen zone? I'm trying to figure out how I can make this work.
What is required (visa?) by Switzerland for US citizens that want to be interns?

A:

You can enter Switzerland and stay there, for 90 days, under the usual rules which allow visa-free visits to the Schengen area for US citizens. The time spent in France under your French long-stay visa do not count towards these 90 days, see e.g. Does tourist visa (90 days) apply after a long-term visa ends in Schengen countries?
However I don't think you are allowed to do an internship in Switzerland without a Swiss visa/authorization (especially since I seem to recall that internships must be paid there), even during the validity period of your French visa.

