This story happened to me when I was 15 but it didn't seem to be evil, it seemed like it just wanted to tell me that it was there and that it was just visiting. About 2 years ago I was home alone (I have a graveyard in the backyard.) I was waken up to this loud bang coming from my room (I was on the couch - one storey house). When I got up and investigated my room, I found nothing wrong so I was thinking the house shifted but then when I started to walk out, I heard my name and I turned around and I saw this soldier (in my graveyard we have soldiers from WW2 and the revolutionary war), but then when I blinked and he was gone. So I just figured I was dreaming or just crazy.
But then the next night I was laying in my bed and I smelled a gun-smoke kind of smell and then it vanished and I got up and went and told my mom and she just blew it off like "it's not true your just imagining it".
But then about 2 weeks after I told her, I was with her and we were sitting in the kitchen just talking and I heard the noise again and this time, she kind of believed me and said she was sorry about not believing me when I told her the first time. So 2 years later this spirit hasn't come back, so I figured he was just visiting.
While reading your story, I recall my deceased grandma's similar story about her non-human suitor, an "AGTA" a very black man/entity. According to her, this happened about a few years before the WW II hit the Philippines. That time, she was still recuperating from the delivery of her 2nd Baby and one day, just out of nowhere, this "AGTA" appeared to her, wooing her. Their neighbors taught she is suffering from a mental illness because she would suddenly shout "go away, leave me alone" because this entity will keep on appearing infront of her (the people around her could see him except her). All others except my grandpa believes that his wife indeed was courted by some entity so he sought the help of an "albularyo" or witch doctor. The albularyo was able to drive the entity away and my granparents lived peacefully for awhile until WW II came. The war went on for four years with my grandparents and few of my uncles who were already born that time would spent most of their time hiding in their "air-raid shelter". When the war was over, the Agta made his presence for the last time. He appeared wearing a ragged soldier's uniform. He appeared just for a few minutes, I guess just to say goodbye to her. After that, my grandma didn't see him ever again...
Chinchai