I don't know of any that use an adapter, or of an adapter for the Wii sensor bar.
If you're a tinkerer, you could easily wire up an adapter to any sensor bar, you just have to match voltage output of the adapter to whichever sensor bar you use. I believe the wireless ones are all 6 volts, while the Wii one is 7.8 volts, most voltage adjustable universal adapters will run these voltages, though they usually step from 6v to 7.5v to 9v, 7.5v will run the Wii sensor bar, and some have even just added a 9v battery snap connector to the Wii sensor bar, so 9v should run it ok too. The adapter has to be 200mah or higher. The easiest way to do it is to wire a socket to the sensor bar that matches the plug from the adapter, or you could hardwire the adapter right to the sensor bar. If you go poke around Radioshack, they would have whatever you need. Of course if you don't have a soldering iron, or don't know anyone who does who could help, then you would have to use crimp butt connectors to join wires instead of soldering.
Unfortunately the DIY route is the only way to get a sensor bar that will plug into the wall as far as I know, but it has been done before.
See here for 9v battery mod (post #1):
And here for wall adapter mod (post #17):