Like the previous responder said, you may want to clarify a bit more in order to get a more accurate answer to your question.
A social helper would be general term used to describe an individual person or group of people who are committed to helping or assisting others in need. I would also assume that this term could apply to anyone who has the intention of helping society as a whole.
I think an example of a social helper may be a teacher. Teachers assist students everyday, in many different respects. Not only is it a teachers job to teach content of a specific course, but it their responsibility to help in the formation of productive members of society. While teachers get paid to perform a specific job, many go above and beyond what they are supposed to.
Other examples of social helpers may be volunteers in numerous settings and social workers.
To provide you with a good answer I would need to know in what context you are using the term social helper.
Generally, a social helper can be someone who spends their time assisting others to better society. An example would be someone who works for a soup kitchen or homeless shelter. They donate their time and provide a service to benefit others.
Another example would be a social worker. A social worker is someone who provides counseling and assistance to those who are going through difficult times. They help them with viewing events in a realistic manner, coping with them and increasing effective communication.