It reminds me of a very peculiar thing that my grandmother used to tell. At that time she was cooking the food in wooden stove where wood was used to create fire.
Sometimes the wood burnt with peculiar vibrations and flares and she commented that someone was remembering us and a guest might be there at any time.
As mentioned by Ramachandran, we will be always under the surveillance of God. he will be watching every movement of us. We feel that nobody is looking at us. A cat while drinking milk closes its eyes and thinks that nobody is watching it. But it never knows that its eyes are closed but not the eyes of people around.
So never think that nobody is listening or watching you. Keep thinking that you are under watch 24/7. Then you will be more safe and careful.