This two part print will hold and protect a standard MR16 low voltage LED downlight. Note: do not use it with a halogen bulb... It will melt. I used it as a worklight on my Colchester lathe. I purchased cheap LED clamp on type reading light from a well known hardware store but the COB chip in the head of the lamp failed after just a few hours use and since I had modified the flexible stem and switch I couldn't return it. I tried and failed to find a suitable replacement for the LED chip and decided that standard downlight bulbs were easier to replace in the future. The end of the housing has a 12mm diameter socket for fitting over the flexible gooseneck but you can modify the Inventor source file to suit what you have.
I have also included a two part print which allows for a rocker switch to be fitted directly to the stem of the flexible gooseneck. I found a rocker switch in my scrap box which was about the right size so the print was modelled specifically for that switch. I have included the original Inventor parts so you may be able to edit the parts to suit a switch that you might have.

Both parts can be printed without support material by placing the largest diameter face down on the build table. The bulb can be inserted in the housing and the cap is held on with some small self tapping screws.