Micah lived in a time when lifestyle choices where "anything goes" ... maybe not unlike today. He chose to set up a shrine (including idols) in his home. He hired a priest to make it legitimate. The priest's greed allowed him to set aside what is right regarding proper worship and obedience to God's will.
Today there are a lot of people who consider themselves believers yet they set aside what is right regarding proper worship and obedience to God's will. Their idols may not be images or objects of worship - their idols may be self-serving ideals they keep in their hearts. Just because it feels good and has been legitimized by some authority, doesn't make it sanctioned or sanctified by God.