I know you're going to tell me to do this another way but I don't know
how strongly you're going to say it.

I am going away for a few days, and I didnt' expect this. I planned to
put a timer on my kitchen ceiling fixture. The one I used to have worked
fine but failed, and the one after that failed too (after about 15 years
each). The one I bought recently turned out to be no good for CFL's so
I just got another one and it wants the neutral wire.

Only for the current that it needs to run the internal clock. Not much
more than a watch battery puts out, right?

All I've got available is the ground wire. How bad is it to use that
until I can run a neutral wire?.

I already have a 12 or 14 gauge wire running to this box that used to be
used for another purpose, but no time before I go away to scope it out.