Randy those are an approved and listed plug together connector for nm wire. I have seen and connected them on several modular manufactured homes...(not mobile home any more [Linked Image] home owner took offense at the term mobile home) they are usually located in a junction box with correcponding numbers onthe wire ends where the 2 halves of the home meet in the attic area usually in a closet. we have some repair connectors that are similar that are rated for in wall use , though ive never tried it,dont trust them, and they are very spendy. the duct tape is not required for the connection that is the high level of craftsmanship from the repair person doing this workin the second picture [Linked Image]
edited for clearity and psellinng

[This message has been edited by sparkystudent (edited 07-25-2004).]