Mine shocks me every time I see it....... its an amazing piece of machinery.
but seriously, if you think it might be static discharge, check the handlebar riser clamp gound wire and lugs. pull your control housing apart and look for wires pinched by the housings or where the main housing harness routes through the dimple in the bar; under the bracket that clamps the control on the bar.

 

You're probably not going to get static discharge sitting on your motorcycle. I would lean more towards something isn't properly grounded on your handlebars. The reason its not doing it everytime is because you're probably not grounded the same way each time your ride...the system is using you as a better ground every so often. Electricity has to find the easiest path to ground. So its either a wire that's pinched or cut(either a + or negative).....meaning you have to look at both sets of wires

 

Static from the plastic seat.

 

+1 on grounded spark plug or coil wire...if the +12-13V battery voltage was shorted to ground (frame) and/or minus battery, you would get a really large arc and lots of melted metal...no way you wouldn't notice...

 

Since you're still under warranty, why don't you have your dealer check it out?

 

+1 melt something or blow fuses or trip breakers. Look for coil or plug wires shorting.

 

its onlyt 12 volts cant be felt put your hand from one battery terminal to the other, feel anything? NO! its only 12 volts, thats not your shock, poss, a coil/spark plug wire, or most likely static electricity, has the humidity been low in your area lately? you can also check grounds for your handlebars as they might not be grounding the static. its not your bike most likely

 

FLHR, FLHRC, FLHRS, FLHRI, FLHRCI, whatever ....... call it like it is, it's a ROAD KING. As far as your shock, I'm betting on some weird static or some coil/plug bleed off.

 

Guys, the same thing happens to me. I have an O9 SG. I have determined that it only happens when I am driving under power lines. I actually stopped under some power lines and got a shock every time I touched the switch housings. I don't think it happens any other time. What could be the cause of this?

 

Seriously, I experience the same thing on the way back from a trip to the Blue Ridge Parkway. Last day on the highway I took my gloves off and felt this sensation in my right thumb where it touches the switch housing.
I thought it just began but then relized it was the first day w/o gloves.
I thought it might be a short related to water intrusion since on the BRP it rains every other day.
I thought it may be due to recent installation of chrome switch housings by dealer.
Well, dealer graciously agreed to test. Spent a day spraying water, road testing and even taking everything apart. He found nothing.
BTW it went away before I even got to the dealer and hasn't returned four months later.
I know this doesn't help much but I know that it's really happening and the solution may prove elusive. If you do solve it please post. I'd still like to know the cause in case it happens again.