Before I start closing everything up with drywall in the basement, I was wondering how I could go about testing the 18-2 bell wire used for my central vac switch? I just want to make sure the connection where splices had to be made are installed correctly.

If the vac isn't powered up or connected you could put a 9 volt battery on one end and a test bulb on the other end, if the bulb lights you got it.