I will start talking about my experience with Openmind projects, saying that I did not have any particular expectations. Being my first experience of volunteering, I was ready to expect anything, so I would have accepted even a possibility of a not positive situation. It wasn't too easy to find the right association. The internet world is full of false non-profit organizations and / or other companies whose main purpose is to gain money. Most of them will charge you a lot of money also for short period of staying.