Volunteer can usually design their own job, depending on their interests, skills and experiences.  Technical skills, while useful, are not that terribly important for a frontline volunteer.
It's very important to bring a caring and respectful approach to this work. Residents have frequently come from a very traumatized background in their home country and while travelling.
Patience and persistence are a must. Counselling skills are very valuable.
You may be exposed to some very difficult stories. Be careful of your own mental health. Ask other volunteers for help when you need it.