Here is the quote from Walthers home page. I had this idea but Brawa beat me to it! 
Andy
QUOTE:
"Brawas new Pin Socket System has made lighting up your layout easier than ever before! This new system can be added quickly and easily to any layout or diorama. All you have to do is drill a hole for the socket, hook it up to a power source and plug the light of your choice in. Thats it! The Pin Socket System is set up to allow 10 of play. Adding lights on hills and inclines is no longerdifficult because you no longer have to worry about drilling holes at a perfect 90 angle to your workbench; any hole will suffice. The socket contains a pivot which allows you to tilt the light up to ten degrees. Once the socket is in place, just plug in your light and angle it the way you want. Once the socket is in place, any of the other light poles can be placed in it at any time. All you have to do is pull the old one out and plug the new one in. You can change the look of your layout in a matter of seconds. With five different styles available from Brawa, you can choose the light that best fits your layout or diorama. You can pick from the Elliptical Lamp (#186-5800), the Station Light (#186-5810), the Park Light (#186-5820), the Street Light (#186-5830) or the Wooden Mast Light (#186-5840). Each light comes in packages of three to help you line your streets. "

Andy
QUOTE:
"Brawas new Pin Socket System has made lighting up your layout easier than ever before! This new system can be added quickly and easily to any layout or diorama. All you have to do is drill a hole for the socket, hook it up to a power source and plug the light of your choice in. Thats it! The Pin Socket System is set up to allow 10 of play. Adding lights on hills and inclines is no longerdifficult because you no longer have to worry about drilling holes at a perfect 90 angle to your workbench; any hole will suffice. The socket contains a pivot which allows you to tilt the light up to ten degrees. Once the socket is in place, just plug in your light and angle it the way you want. Once the socket is in place, any of the other light poles can be placed in it at any time. All you have to do is pull the old one out and plug the new one in. You can change the look of your layout in a matter of seconds. With five different styles available from Brawa, you can choose the light that best fits your layout or diorama. You can pick from the Elliptical Lamp (#186-5800), the Station Light (#186-5810), the Park Light (#186-5820), the Street Light (#186-5830) or the Wooden Mast Light (#186-5840). Each light comes in packages of three to help you line your streets. "