I had posted these in the past.
Image: http://www.nachi.org/bbsystem/usrimages/P/Picture0091.jpg ]
Image: http://www.nachi.org/bbsystem/usrimages/P/Picture0081.jpg ]
Image: http://www.nachi.org/bbsystem/usrimages/P/Picture0061.jpg ]
Image: http://www.nachi.org/bbsystem/usrimages/P/Picture0071.jpg ]
Here is a spin on the same concept found by an Inspector in Maryland…