This will work on both points and CDI. Did the whole thing as a .jpg, so if there are any typos, I can't easily fix them.
The reed switch is your typical Normally Open house alarm door switch. You can use the matching magnet if they come in a set, otherwise, any small magnet will work. Just set them in close proximity with the kickstand up. You will have to test to find the max distance allowed for the reed switch to close with the kickstand up. The reed switch will activate the relay. I used the relay because I couldn't find a reasonably priced reed switch that will handle the current draw of the points system. The relay is Radio Shack part number 275-218 and it can handle a 10 amp load at 12 volts. They have a socket available also...part number 275-220. Both items are available in stock at most Radio Shacks.
I'm going to edit my original post.
Here is the key to wiring this correctly for your bike.
Match up your bike to the list below to see how to wire this to your bike:
CDI diagram --- H2 (all), H1D, KH500, and KH400
Points diagram --- All S Series, KH250, all 69-72 H1(wires to CDI boxes, not coil on CDI models...H1B wires to coils.)I got this from Mraxl's resource page wiring diagrams. The diagrams on the resource page are for US models. Double check your wiring diagram to see if your bike's ignition works by either ground or 12 volts and which wire to hook it up to.
I take no responsibility if you wire this up wrong and fry something gotta cover my butt