Ed:
If there was such a plug-in device, it would have to plug into a 220 volt wall receptacle. This is necessary because the signal bridge must bridge two 110 volt electrical phases (this would not work if your home had 3 electrical phases).
I have heard of some people connecting a 220 type plug to the wires on the signal bridge and plugging it into an unused clothes dryer receptacle. This type of installation may function but is not in compliance with the NEC and would not be UL approved.
However, many people also install the amplified signal bridge themselves, without the need for an electrician. This should only be done if you are familiar with your electrical panel though.
Robert
RCI Automation
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