Don’t search your own house. Call your local police department and ask them to help out. They’ll want to know why you think someone is in your house, i.e., the door was open, the door was kicked open, the back sliding glass door is broken, the screen is off my window, etc. If none of that applies and you’re going to search your own house, have 911 ready to go on your phone. Start the search from one section of your house and systematically go through it. Example: Don’t skip the downstairs bathroom or closet and then go directly upstairs. Don’t start upstairs either. Start downstairs and go from room to room before moving on to the next section.