The internet on my wii

try to set your channel to either 1 or 11.set also your router's broadcast setting to 'mixed'.place your wii near router with no interference from microwaves or such.if router setting is set up to allow only selected pc's (or mac addresses),don't forget to include wii's mac address to enable it to have access to the router.if your router password type is wpa,make sure also you know whether it's wpa-psk AES,wpa2-psk AES or wpa-psk TKIP,you need to consciously choose the right one on your wii internet setting.also,you could switch the dns ip addresses around like put 2nd ip address in primary and 1st ip address in secondary.no guarantees,hope this helps.

· Here is a Video on how it is done, if you have done this... i believe it would be the settings on your computer.... are you able to set settings on your switch?
YouTube - How to setup a Nintendo Wii USB Lan Adapter (Remix version)