I will be doing a 6-month internship in Switzerland near Lausanne soon, and I will be remunerated 1000 CHF per month in gross salary.
How much can I expect in net salary?
At the moment we have 5.15% social security contributions and 1.1% unemployment insurance which you have to pay and there are maybe (it depends on your employer) an accident insurance which you have to pay too.
Generally we have in Switzerland not so high taxes, like in other countries, so I think your net salary is a little bit over CHF 900.-.
The first comment, made by jamesqf is correct.
As user "crashwinston" mentioned, the taxes on salaries are not very high in comparison to other countries, but I it is important to add that the social security contributions are minimalist in Switzerland : this means that the mandatory health insurance is not included in them.
For the cheapest health insurance, you will have to pay around 400 CHF/month, with an annual franchise of 300 CHF. This means that when going the doctor (public hospital or private medical practice), you will have to pay the first 300 CHF (as well as 10% of the excess part). The possible franchises are 300 CHF, 500 CHF, 1000 CHF, 1500 CHF, 2000 CHF, 2500 CHF.
Many people from abroad focus on how high are the salaries, but have no idea about how high is the cost of living.
1000 CHF/month is clearly not enough to leave in Switzerland if you don't have additional help or reserves.