Paul:
The bubble light is a 110V AC one. It's wired with a 110 Vac LED light inside the house.
As for using an old 15 Volt one.
Use a small step down transformer to get the 110V ac down to 15 Vac.
You'd get an AC adaptor like this one from Radio Shack
http://www.radioshack.com/product/index ... Id=3875409The above is only for example it is pretty expensive, one could get one more better priced. This one will work but I would not spend the extra money. Easy to find a Radio Shack around the US.
Then wire that to a C6 (E10) socket such as this
http://www.radioshack.com/product/index ... =CT2032232or
http://www.radioshack.com/product/index ... =CT2032232This will get you running with a vintage one.
Remember Radio shack is pricey. But easy to get.
Recently I saw a reseller on ebay sell a wall transformer and a socket base for not too much.
Seems he sell them all the time.
I'll post a link if I can find it again.
I'm working on this myself to be able to power Nippon light houses one at a time.
I'll post more after the holidays.
Steve