Dear Alexandra:

Thank you for your questions.

1) In most cases people who can sense spirits probably have that ability from improper sources, even if they are not aware of that. In those cases the person should renounce that ability and ask God to take away. If the ability does not go away than the ability is not sourced in God.

In other cases there are some people who have preternatural abilities, are natural sensitives, which must always be used for God. Any use of these abilities outside of that which builds up the Church and serves our Lord will be exploited by the Evil One.

And then there are people who have been given the Gift of Discernment. This is a charism (gift) which is supernatural in nature and beyond human abilities that may discern right from wrong in a remarkable way and also perhaps perceive the presence of demons or human purgatorial spirits that God may allow to linger on this earth (see the essay, Seven Kinds of Ghosts).

In almost all cases, however, the "spirits" that are sensed by people are not human spirits, but are demons

Finally, any of us who are baptized Christians, and thus have indwelt the Holy Spirit, can have a general ability to sense the presence of spirits, that is, demons, by virtue of our faith and the indwelling Holy Spirit who informs us.

2) Haunted houses, and haunted areas, are nearly always haunted by demons and not human spirits. But, in rare instances God may allow a purgatorial spirit to linger in this world. See the essay linked above on the Seven Kinds of Ghosts.

3) If we are in a state of sin God's grace will not be fully available to us. This is easily remedied. All we have to do is to be sorry for our sins, make a promise to try not to sin again, and ask God's forgiveness. When we do that we are restored to a state of grace, which means we are restored into full friendship with God. This means that we have access to the fullness of God's grace. God can answer prayers from anyone no matter what, but we are most likely to receive God's help when we are in his friendship rather than when we are apart from his friendship. This is not because God is refusing to help us or refusing to answer our prayer, but because our sin, which is a result of our own choices, is blocking the way — like a lamp that has the cord severed. No electricity can get to the light bulb to light it. God is a gentleman. He never forces Himself upon us. Thus, if we block Him because of our sin, He will respect our choice. This is the consequence of Free Will.

4) The bad actions of one family member can certainly effect the whole family. This is obvious in the material sense in that if, for example, the father gambles away the mortgage money the entire family suffers. This is also true in the spiritual sense. For example, if a family member brings pornography into the house, which will attract demons, the whole household may suffer in some way.

As for finding a human skull under the house the problem would be legal one. To destroy a human human skull like this is to destroy evidence of a possible crime. Thus, your great-grandfather could come under criminal charges. But, the idea of a spirit attached to this skull is mostly the idea of Hollywood. With that said, it is possible for a demon to attach itself to such an object. The shadowy figure noticed by your grandmother would most likely be a demon and not the human spirit.

It is possible for a demon to attach itself to the family line due to the actions of an ancestor that may have brought the family to the devil's attention.

5) Yes, every human being has a guardian angel. Jesus mentions Guardian Angels in Matthew 18:10. Guardian Angels ministered to Christ in the garden, and a Guardian Angel delivered St. Peter from prison. The writer of Hebrews mentions Guardian Angels in Hebrews 1:14. And Psalm 91:11 says. "For he will give his angels charge of you to guard you in all your ways."

6) Angels do not have bodily form as they are pure spirits. When God permits it Angels can appear as human beings, or they can appear like the traditional winged creatures, or they can appear in any form at all. Should it serve the purpose of God an Angel could appear bigger than a house, but I doubt there is any reason to do so, unless the Angel is doing this to scare a Satanist, for example, by appearing large as a display of power. Even then, it is unlikely. Such things are the invention of Hollywood.

God Bless,
Bro. Ignatius Mary