How do we find a lost pet snake? Well, my first bit of advice is don't lose it. When you build your terrarium and you have your terrarium, it is very important to put a latch on the top. These guys literally are Houdini's. They will get out very easily. Your bigger snakes are very strong. They'll lift the lid off of a terrarium. So you need to make sure that you have a latch on your terrarium, so we don't have to have this discussion.
Now snakes are solitary creatures. They love to hide in things. If he gets out, he's going to go to a very secure, dark hiding spot, which can be the crevice of your couch, underneath the couch, inside the wall, pipes, into your crawl space and they can get anywhere that little nose goes. So they can get into very small places. The first place that you want to try to look is, I would recommend tight spots in the area where the terrarium is.
Now he may stay pretty close to home initially, especially if you're regular with feeding and there's no bait in the house, otherwise he's going to go where the food is. So my biggest recommendation to you is let's try to avoid it. If you can't, then you need to search out all the quiet, dark spots in the house and get creative, because your snake is going to be creative. Always think about getting into the drywall, behind your refrigerators, anywhere where it's tight and dark this little guy can wind up. There's a little helpful hint on how to find your snake if he gets out.