If cameras aren't connected to Wi-Fi, you can still pick them up with your Bluetooth. Just set your Bluetooth to its pairing mode and see what devices it can pick up. Disregard TVs and smart home ...
I'm willing to bet you shot a quick look over at your TV the moment you read the title. Yeah, you read right; your smart TV could have a camera, and here's how you can figure out where it's hiding.