It is scary to experience it for some people. We recently did an investigation where some of the family members were getting their feet touched at night.
I was touched once in 2009 when we were investigating the Diamond Mansion.
I was walking with Sarah, one of my crew members, side by side down this long dark hallway. We were coming to a door we had to walk through when she laid her hand on my shoulder. I turned to see what she wanted and no one was there. She had stopped about twenty feet back to look at something on the wall. It was not a scary incident for me at all. It was like someone was telling me to hold up a minute. I loved it! In ten years I have not been scratched or hurt in any way. Others I know were not so lucky. When we did Sedamsville, one of the crew got scratched down his back. It was about an inch wide and 12 inches long.
Here is one possible theory as to why ghosts do what they do.
What if you woke up one morning and went downstairs to see your family getting ready for their day and no one saw you. They couldn't hear you and didn't know you were right there beside them. No matter how much you yelled or how hard you tried, they just didn't know you were there. Day after day, you watch as they mourn your death. Eventually they move, leaving you there, because for some reason you can't leave the house. Year after year goes by and you get more desperate for someone to know you are there. You would get really angry at some point. What would you do to get someone's attention? Pull their hair. Move their belongings. Turn on their water? Change the channel on their Television as they watch it? Scratch them? Push them, all the while screaming
"I AM HERE!!"