I saw this some time ago and was quite taken with just how much crude wiring you can put in a parcel and still
not have the device detected on the X-Ray machine 
.
Basically if you have ever wondered what happens to your parcelafter you take it to be posted then you are in
good company. Ruben obviously had a very strong urge to find out because he built all this
It looks a little crude but certainly works!
Here's his video of the escapade