A familiar spirit is a demon that serves or prompts an individual. We would do well not to get so familiar with anyone dabbling in the occult (Palm reading, horoscopes, weegie boards, etc.).
Once you leave the path of the Lord and seek other counsel before Him, it is a slippery path downhill.
“Then said Saul unto his servants, Seek me a woman that hath a familiar spirit (Medium), that I may go to her, and inquire of her. And his servants said to him, Behold, there is a woman that hath a familiar spirit at En-dor.”
1 Samuel 28:7
We see an uptick in the occult today. Not even two miles from my house, there is a Palm reader.
Instead of going to God for advice on how to defeat the Philistines, King Saul went to a witch to contact Samuel from the dead.
In the last days, there will be satanic infiltration, “But as the days of Noah (Genesis 6) were, so also will the coming of the Son of Man be.” Mathew 24:37
Jesus warned us not to be deceived. Watch and pray.