How do I log out of Netflix on all devices? Think an old TV is still signed in somewhere.

There's a one-click option for exactly this. Go to netflix.com > Account > find 'Sign out of all devices'. It logs out every device, TVs, phones, tablets, within about 8 hours. For an instant boot of a specific device, use 'Manage access and devices', which lists every active session with location so you can sign out individual ones immediately. Change your password too if you suspect someone else is in, and set a profile PIN to lock it down further.

'Manage access and devices' is the newer, better one, it lists every signed-in device with location and lets you kick them one by one instantly, rather than waiting 8 hours for sign-out-all.

Change your password right after signing everyone out, otherwise whoever had access just logs back in. And check for any extra profiles you didn't create.