Can alien Greys or Reptilians or Arcturians possess a person to gain a measure of control and hide within their body energy while doing it?

This phenomenon of possession can be done by all three, for it merely requires control of the human mind to put the host's mind in abeyance to take a backseat and willingly stand aside or be actively suppressed. In a way, it becomes inoperative and then the alien being is at the controls and can make the body do what it wishes and to speak and carry out various functions. So the ability to connect to sensory apparatus is not required because they can maintain their intuitive awareness of the surroundings. And so they need only command the body through the mind and they can function quite well. This is a skill that requires some practice, but many aliens are adept at this and it is very routine for them.