How do I go about finding my homes history? I have seen a child's spirit in our home on about three or four occasions. Now my teen daughter has told me that she was terrified because she saw a child in the home two times.

You can check with your county's assessment office and they will tell you who lived there prior. Or you can type (your county) property assessment office in the search engine and try to do it yourself. This is a sample using my county
Allegheny County Assessment
Then you type in the information and the next page should have some tabs with one that says previous owners.

Also Ghosts aren't limited to material things so if your house was built after a prior house they could have lived in the previous house.