For methods of self-lighting on exit from sheath, look into the world of magic.
There are many tricks that involve a self lighting mechanism - such as the flaming wand from jacket pocket or the flaming wallet/book type effects.
Most of these tend to use the traditional flint/spark ignition found commonly in lighters that are rigged in such a way that as the wand is withdrawn or the wallet is opened the flywheel on the flint is turned.
Only a few use the peizo 'electric' spark.
unfortunately if you are usisng paraffin (i think you guys call it kero) it needs to be 'warm' for it to ignite from such a little spark cos of its low flashpoint. Most magicians use lighter fuel for this.
Its only a pointer but i hope its in the right direction. Try experimenting with different methods. Im off to a magic shop in a few minutes so i will ask them for some advice for you if you like but cant promise anyhting cos you know what magicians are like!
Gruff 