No Clue Where He Came From

Really strange thing has happened at our house tonight. We went to some friend's house because they wanted DH to officiate over renewing their wedding vows. We had a nice time and stayed a couple of hours. When we got home around 10 I came in the front door and went into my bedroom. My BC was asleep by the bed as usual. Then I saw something run past the door to the office. My BC caught sight of it and went to investigate, as did I. It was a brown puppy! Looks like a Brussels Griffon. Likely a cross of a small breed with a rough coat and a boxer. It has a protruding lower jaw and a rough coat. It is a male that looks to be around 3 months old and very skinny. Somebody had to walk up to my house, open the front door and put the puppy inside my house. Nothing was bothered. We had valuables , computers, guitars, a gun, DH's meds, ect. sitting out but nothing had been touched. Just this puppy in the house. I half expect it to be a joke that we will hear about tomorrow. Anyway, the pup is in the bathroom with my BC and they are sleeping. We tried to put him in the utility room but it has no door between it and the kitchen. We blocked it off with a piece of steel grating about 3 1/2 feet tall but he climbs it. If it is not a joke and somebody has put it off on us, we will have to find it a home. Like I don't have enough to do. It is a strange thing. I will not leave my door unlocked again.