Thanks for reaching out. If your Chromecast is still connected to the network and you would like to disconnect it, please see the steps below:
You may also reset your Chromecast so it will be disconnected from the Wi-Fi network. Please check this support website article to see the steps on how to factory reset your Chromecast device.
I haven't heard from you in a while so I’ll be locking this thread if there’s no update within 24 hours. If you're still experiencing problems, please feel free to start a new thread and we'll be happy to help.