Placing recessed lighting

I realize that this is a really dumb question, but I've placed recessed lights on my plan but can't figure out how to precisely place them. I thought that by selecting one light that I'd see temporary dimension lines but that doesn't seem to be the case. What am I missing?

There are more than one way to skin a cat of course.

I commonly draw a grid using CAD lines placed on a custom layer (electric layout or some such).
Then place my lights using that layout grid.
There are fancier ways but this is what I do.

DJP

Hearthstone:

Here's a couple of images of things you can use to precisely place your electrical stuff:

Attachment 45503Attachment 45504

To use the Tape Measure tool, you might have to zoom in to make sure you are dimensioning from the right layer or surface.