What does it mean when a ghost reveal its self to you?

One night several years ago, my mom was visting a friend and after the vist we all walked out in front of her house( the friend ) to get in our car to go home. while we were getting ready to pull off, I notice a man standing in her (the friends ) backyard standing there looking a us. (not moving the whole time we looked at him)...BUT he did'nt look like an ordinary man...he was dressed in traditional native American garb, ( feather headband, no shirt, long black hair, vest leather pants etc. ) and it was a VERY cold night there in Detroit Michigan...so he looked VERY out of place LOL! After a while I figured It may have been a ghost, and I was afraid it would follow me home!! Talking to a few family members, it seem that the house was haunted anyway...and the house had a "evil presence" and all that....so yeah...He manifested as a solid human, light reflected off of him...what does it mean when a spirt does this? :^)