Here's how to transform a regular maglite into a UV maglite using a LED. This is a very easy Instructable and may cost only a few dollars.
Step 1: You Need...
~Needle nose pliers
~1/4 in drill bit
Step 2: Disassemble
Disassemble the MagLite
Step 3: LED
Resise the led's leads with pliers and hands
Step 4: Drill
Drill the hole wider and make sure the LED fits through easily
Step 5: Reassemble
Insert the led into the holes and it doesn't work, switch the leads around. Then reassemble the light together.