Hey.. I'm wondering, I wanna buy a stand for my condenser mic, but I want the stand to connect the ceiling.
Like.. A boom hand stand but instead of being on the floor, connect it to the ceiling.
If you dig around a bit you can find boom stands that screw onto the desk rather than clamping--on of those could be screwed to the ceiling just as well--though, due to weight, I'd suggest that you find a joist rather than just going into the sheet rock.
If you use a mic stand that has the heavy round bottom base, the bottom of the upright piece is threaded, just find a corresponding female part that can be attached to the ceiling joist. Note that it is going to be 'stuck' in that one location, though. I think floor stands are much more practical.
The male part is the upright of the stand. The female thread is in the base. I don't know what the thread size is, but it probably is a standard pipe thread size.
⅝″ 27 threads per inch (tpi) Unified Straight thread (UNS, U.S. and the rest of the world)
¼″ BSW (uncommon in the U.S., used in the rest of the world)
⅜″ BSW (uncommon in the U.S., used in the rest of the world)
Above are the general mic stand threads and they are different from pipe threads (mind you, the USA/UK/EU makes the whole situation a clustercluck)
Re fixing to plasterboard (what we call sheet rock) I agree you must find a joist but in general you can get a very good fixing if you use a secondary plate of 19mm high grade ply and fix that with at least 4 aluminium plasterboard fixing (they screw into the PB then a supplied selftap goes into the ally fixing) NB do not buy the plastic version, or if you do, buy a chocolate teapot as well to use at breaktime.