Step 1: COVER THE HOLE AND ANY HOLE IN YOUR HOME IT CAN ESCAPE THROUGH (duct tape will work)
Why? Well this stops him from getting out if he is still inside.
Step 2: Look under the house (it should be easy, trailers usually have a way under them) but bring something in case of poisonous snakes or spiders)
Step 3: Search around the area in anything that seems like it would be tight enough for him (under logs, bushes, etc)
Step 4: Upon exhausting the outside, look in every nook and cranny at your place. I keep my snakes in my room and before getting a rack my adult male would escape sometimes, but he was usually in my closet or between my bed and the wall (or under the bookshelf).
Step 5: If you don't find him, stick a rodent in a cage in your house and outside of your house, this may attract him. (be within view of both)