One Wireless stereo speaker

I have a customer who wants to install a stereo pair of speakers using his Onkyo receiver as a source. I can wire one speaker directly to the receiver. However there is a fireplace between the receiver and the left speaker. There is no rug, There is no basement, there is no attic.

Is there a Sonos wireless solution to this problem, Additionally, this is a “Budget” installation.

If not a Sonos solution, does anyone know if there is such a thing a a set of bookshelf speakers that uses wireless technology to send a signal to to the “other” speaker     ie. that doesn’t require a wire between speakers?

Thanks

Gene