I'm a Hungarian citizen, with the possibility to take a 6 month contract job in Switzerland. What type of visa do I need to work there? What is the process to acquire it?
If you are a citizen from an EU or EFTA country, except Bulgaria, Romania and Croatia (which includes Hungarian citizens no matter where they reside), you don't need any visa to enter and take up work in Switzerland for the time being. The bilateral agreements with the EU are still in force, which means you have a right to work or contract there more-or-less as you would in EU countries. In practice, you do however need to apply for a permit after you moved to Switzerland.
The Swiss people recently voted for a constitutional amendment that could change all that but as of April 2014, this amendment hasn't been fully implemented and only the part about signing new agreements is already effective (which is why Switzerland did not ratify the extension of the agreements to cover Croatia and the EU froze talks about various other agreements).