Do CCTV Cameras Make Cities Really Safe?

When I am at work, I worry incessantly about my daughter left alone at home with a nanny. I can perhaps install a CCTV at home to watch over her but that may not be a practical solution as I cannot be glued to the monitor while I am at work. But it would be great if I could receive an alert each time she moved close to an electric switch or the cooking range or wandered onto the balcony. I could then watch her and call home to alert the nanny. This is just one instance when safety is of such