My wife and I recently bought a house where we will shortly live with our 2-year-old son and, when our second child is born in a few months, a baby. The house is currently rented to tenants we know to be smoking crack cocaine. Is there any danger to us, once we have moved in and after the tenants have left, from second hand smoke trapped in the walls? I suspect not, but want to be sure. Thanks.

The risk is with meth, not crack.

What is the risk with meth? How would we know (from the empty house) if there are any dangers lurking in the walls? Thanks.