You read it right, even light bulbs present in your room can lead to leakage of your data. We continuously see new innovative methods being develop to exploit data.
Some methods require physical access to your machine but in this even physical access is not required. This is special kind of technique called Lampophone and by analyzing vibrations in lightbulb, evesdrop on data is possible.
When we speak it does emit some waves and it can induce some vibrations in bulb which can be decoded when correctly listened to.
You can imagine that light is very necessary element of our daily life and it is normally present in our rooms. So if you were to speak anything sensitive in your room in the presence of light, you have chance of your data being leaked.
Here is full functioning of this idea and how it can be done in detail:
The future seems very less secure because with these intelligent developments our security gets more weaker and we definitely need new set or completely new approach towards security because right now there are many loopholes.