What is the model number of the TV?

It almost definitely will not be PnP - the WiFi adapter will require some sort of driver to run, it is possible that the TV supports certain devices but it definitely just will not support "any" device that gets plugged into it. USB adapters are very different to Ethernet in this respect - using Ethernet you can plug into any router and it will just work, but not with a USB adapter.

One option may be one of the Ethernet to WiFi bridges, like many people use to connect XBoxes and similar. These would provide a relatively neat solution and require no specific support on the TV, just plugs into the Ethernet port.

If you have the model of the TV though I can do some further investigation.