You buy cctv in your house. You go to house. It is night.

(There is an way avoid the intruder, Hide in the closet or locker, no light.)

(You have to wait hours to call police because it's error, the intruder possessed it. and police will fix it right away not in your house.)

(phone will happens to alert the intruder any minute if you answer the phone but there is no response for some reason.)

(if you turn it off, phone will stop working but. It will turn it on and alert the intruder.)