Thanks for the tips. In no particular order, here are some additional
answers/observations. Went to my local hardware store and ran the
toggle bolt idea by them...pretty much didn't like the idea.
Stability, ironically enough, didn't seem to be the big issue, as much
as concern about the toggle bolts not being grounded. Anyhow...it was
suggested I try the same thing as the last person's remark --
electrical box with opposing "arms" that spread between the joists.
Ended up buying this. My problem still remains on locating my
joists...complicated by the fact that my ceiling is popcorn, and I
can't get a reliable reading on my stud finder. Was also suggested
using the sensor on the wall and following up to the ceiling...that's
my next step.

The question on why I can't access the area above my ceiling is a good
one. I have one attic access door and when I get into my attic it runs
the length of the upstairs, but then "dead ends" where this room
starts. Don't ask me why...just a peculiar design I suppose.
Anyhow...I'm still stuck. Would LOVE to get in above the ceiling and
do it right as the first person suggested, but just isn't a
possibility.

Will see if I have any luck finding the joists.