Sunardi, I think your question is too broad. What do you mean by "doing something wrong?"
Do you mean committing a crime? A violent crime? Someone yelling at another person? Someone lying to another? A child disobeying his parents?
I think many of the things a person would consider "wrong" is probably not your business to get involved with. However, if you see someone assaulting someone else, that's a different story.
You'll have to define what you mean by "wrong."