Have you ever wondered what a Wi-Fi signal could do apart from just providing internet services? Here is a thing which you must know, And that is scientists from Michigan State University and the Nanjing University in China have discovered that it is now theoretically possible to accurately detect keystrokes with the help of Wi-Fi signals from a plain normal router.
Also, It is being said that when there is an environment with minimal signal interference. Then it would be advantageous for a hacker to find out the key hits of the victim and steal their passwords and data with the help of it. Basically how this happens is, when an environment is with a minimal signal that is with minimum signal interference then the signal of the Wi-Fi can be used as disruptions in the signals to detect the keys.
This is absolutely legit and also tested by the scientists before. Recently this technique was tested by few scientists in a room. With minimum signal interference, they got positive results in finding out the presence and momentum in the room.
Also, these Wi-Fi signals have been used for various purposes just like disruptions, Recently these signals were used to recognize and read hand gestures, Along with lip moments. So with the help of this techniques, one can find out the accuracy of signals established in scientific circles.
The results were out, And they found that the accuracy varies from 77% to 97.5%. Basically, the accuracy percentage is based upon the environment and typing speed. For example in an environment which has very less momentum and a person with slow typing speed then the system’s accuracy was spotted at 97.5%. Whereas in the case of normal world and user with fast typing speed the system spotted the accuracy between 77.43% which is of 30 training samples and 93.47% of 80 training samples.
Terry Ts 
Rudhra Nandu