I am not that familiar with wireless speakers other than Bluetooth speakers i use to connect to my phone/laptop etc. I am going to make a few assumptions, please correct me if I am wrong. Your wireless speakers communicate via Bluetooth or are of the wifi variant. I am assuming they will have a component that will interconnect to your Receiver/preamp/pre-pro etc. I am guessing they will connect to the "tape-out" outputs? They will convert the line level output signal to either Bluetooth or a "MAC/IP over WIFI" signal. Your speakers will have a built in Bluetooth/WIFI receiver which will then convert the Bluetooth or WIFI data stream back to analog and amplify the signal before presenting it to your speakers. If this is the case, then I don't believe you require a switch box . If your wireless speakers operate in a different fashion , please provide some more information and/or the make & model. I sure someone here can help you out.
Cheers,
Scott