Tpoppa, Mep, & others,
http://www.all-spec.com/products/GT-16.html
http://www.greenlee.com/products/DETECTOR%2540c-VOLTAGE-%2540dADJUSTABLE-(GT%2540d16).html?product_id=17647
There is a need to make sure the AC Voltage Hot wire is not too close to other wires when using a non contact device...