In I Samuel 19:13, why was there an idol in David and Michal's house? I know Saul erected a monument for himself in Carmel (I Samuel 15:12). Did Saul and his children worship other gods?
The Hebrew word teraphim is often translated as a "household idol," but some translators, such as Koehler-Baumgartner, think that it is better translated as an image. The argument is that the word applies to any statue of a human or a human bust. Now, many idols were done as human-like statues, but it doesn't follow that all statues were idols. You'll find that the New King James version takes the more neutral approach of translating the word as "image" instead of imposing an implication that might not be proper.
But if it was true that the image was an idol, then it is further evidence that idolatry remained a problem in Israel. I would have to assume it was there because of Michal and not David.