I actually had to install some of those clock receptacles a couple of years back for a lady who wanted to put some of those special lights over some pictures on her wall. That was the first time I had used them in years and had a heck of a time finding them locally. Now it seems everyone carries them and I can't go anywhere without seeing them on the shelf. I think I still have a couple left over from that job, but I really don't know when or if I will ever use them again.
