What can we do about family members who visit and talk to ghosts and give readings in our home?
The answer to your question will be given in two parts.
Avoid The Occult
First, it is important to understand that ghosts, demons or evil angels are real beings. They do exist. We would encourage you to read a previously submitted question and answer titled, “Are Ghosts Real?” In the book of Leviticus, God warns us to not have anything do with any activity associated with the occult. That is, we are strictly prohibited by God from having to do with mediums, spiritists, divination, one who practices witchcraft, one who interprets omens, a sorcerer, one who casts a spell, or one who calls up the dead. Therefore, this will also include ghosts.
How To Respond
How should we respond to someone who is involved in the occult? First, we are not to get involved in the occult in any way. That is the message of Deuteronomy 18:10 where God adds these words about those who are involved in the occult,
There shall not be found among you anyone who makes his son or his daughter pass through the fire, one who uses divination, one who practices witchcraft, or one who interprets omens, or a sorcerer, or one who casts a spell, or a medium, or a spiritist, or one who calls up the dead. For whoever does these things is detestable to the LORD. (NASB) Deut. 18:10
Second, we are not to have an ongoing relationship with anyone who denies that Jesus Christ is God or does not continue in the teaching given to us in the Bible. That is the message of the following passage.
If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting; for the one who gives him a greeting participates in his evil deeds. (NASB) 2 John 1:10-11
However, this does not mean that we should not talk to someone who has been involved in the occult. As Christians, we have a responsibility to tell them about Jesus Christ. But that does not mean that we should spend social time with them. We are not to have them in our home, “hang out with them,” or “do things with them.” It is okay to spend time with them for the purpose of telling them about Jesus Christ.
Those are the key principles. But the difficult part of your question is that your relationship is with people who are in your family. If you are one of the parents or head of the household, then you should stop them from continuing with the activity in your home. If you are a child in the home, then you could appeal to your parents. If they do not respond, then you have no choice but to remain and continually ask God to protect you and change the situation. If you are old enough to be legally considered an adult, then you should leave the home if they will not stop. It is best to honor God. This is a very difficult situation. Jesus warned us that families would be divided because of Him (Matt. 10:35). We will pray that that does not occur for you.