Both my spotted pythons have escaped 2 or 3 times, i found them each time in an 'ad bag' bag within 5 feet of the enclosure. So after the first time i started checking in the bags but still wouldn't find them. But every time so far i'll be sitiing in the living room and notice the bag move 2 or 3 days later and i find them. I've heard of people putting a food item in a paper bag which is on top of a heat pad(make sure it doesn't get too hot). The reason you use a paper bag is so you can hear the snake inside of it and go scoop it up.
Good luck...it will surely turn up when you least expect it
0.1Burm, 1.2 Argentine BW Tegu, 1.2 Beardies, 1.3Boas, 0.0.1 Spectacled Caimen