There are a few things that could be going on when a stray dog shows up to your house. They may be lost and looking for their way home, or they may be seeking out food and shelter. Either way, it's important to take some time to assess the situation before taking any action.
If the dog appears to be friendly and is not showing any aggression, you can try to see if they have a collar or tags that might give you a clue as to where they belong. If there is no information on their tags, you can check local lost-and-found listings or animal shelters in case someone has reported them missing.
If the dog does not seem Friendly or you're not comfortable approaching them, it's best to call Animal Control for assistance. They will be able to help determine if the dog is truly a stray or if they are possibly dangerous.