This video is by a security researcher named Marcus Hutchins and he's been sharing videos of inside secrets to his 33.5 million followers on how to feel safer.
We've all heard and seen the news stories about people finding hidden cameras in their vacation rentals and he posted a video on how to find them. His advice is to start looking for cameras in places where a creeper would want to see you (the shower/bathroom, dressing areas and the bed).
Then he goes on to show you the method you can use to see if there is a camera hidden in a device like a fire alarm (right above the bed) or an alarm clock. Check it out below and always be aware of your surroundings!