It looks a little bit pricey...However, I don't know what they have done electical wise. Do a search here or go to the Monster list of Halloween Projects and look for motion sensor info. There is a lot of information on how to convert a standard motion sensing light.
If you're going to spend that kind of money I'd go for a prop controller
I picked up one of those motions sensors with the light attached at Home Depot (less than $20) and found a schematic for wiring it to the hot / cold water valve from an old washing machine. The hot cold valve controlled the air from a compressor that went into a pvc cylinder I created like this one.. props1
Try this post from Beelce on power strip hack for motion sensors like the one you saw 4 sale; Motion Sensor / Power Strip .. Hack - HauntForum.com
Pick up a power strip for $6.00 ( make sure it has screw not the snap together cases,they break & are hard to deal with )
The motion sensors are lik $20, although to get a short time you need to set it on test for 5 sec on, shortest time
i buy the auto motion light switches ( cheapest at lowes over HD for $16 ), they have a 4 sec to 15+ min on feature that is adjustable
& a senor that is adjustable for sensitivity of motion sensor. I find these to be the best buy & with most timing options for the price !
here is a couple other sites to fest your imagination to build !! HauntProject.com - Your visual source for Haunting How-To's Monster Page of Halloween Project Links
you should find anything your twisted lil heart desires to build !!
This is really easy to make. The simplest way is to just buy a motion sensor light (make sure the time adjustment suits your application) and put plug adapters in the sockets. Add a power cord and you're done! One other thing to check is the reset time on the motion sensor. Most reset instantly which can cause your prop/effect to cycle all the time if people are walking by.
I just made two prop controllers using motion sensors from security lights and time delay relays to control the prop time. I use the motion sensor time adjustment to control how often the prop activates. It's a bit more complicated that way but not too bad.