If you have a couple normal heatpads place one on the floor on both sides of the doorway to the room they were in. Toss some clean crumpled up towels onto the heatpads. Get up at various times of the night and check the towels for your snake. It works quite well. The snake will likely follow along the wall, crawl in behind and up under stuff, but when it finds it's way to the doorway and find the warm towels, it will crawl into the mass of towels and you will find it. It's a good idea to leave a source of water down for the snake too.

Keep in mind, if you have cats or dogs you may want to put them in a room or area where they can't find your snake while you sleep.

To put your mind to ease, as long as your have no holes in the walls or vents that lead directly from the inside to the outside, most lost snakes in a home are found in the first few weeks... sometimes as long as 6 months later.

Rick