Amazon.co.jp: 【Nintendo Switch対応】LANアダプター USB for Nintendo Switch : ゲーム
Ugreen Nintendo Switch OLED RJ45 Cat6 Ethernet Cable - 3m - Black
有線でのインターネット接続方法|Nintendo Switch サポート情報|Nintendo
Amazon.co.jp: Nintendo Switch Main Unit Dedicated Wired LAN Adapter & PD Rapid Charging, 2-in-1, 10/100/1000 Mbps, Ultra High Speed, Gigabit Ethernet (RJ45+60W PD Compatible) [Dock Not Required] : Computers
ユニニンテンドースイッチ(ライト)ワイヤーネットワークアダプタ、イーサネットUSB Cアダプタ - uni
LANアダプター for Nintendo Switch【Switch】|の通販はソフマップ[sofmap]
Not sure if this has been posted before, but USB C-to-ethernet does not appear to work with the Switch : r/NintendoSwitch
How To Set Up Nintendo Switch Wired Connection (LAN Cable)