Can I use a jack to mini-xlr to use a guitar in a wireless lapel mic bodypack?

Question

or will I need to buy a wireless system specifically for guitars

Answer 1

You might be able to do it depending on the model of the bodypack - but I would not try it.  The problem is that many bodypacks supply "phantom power" to the lapel mic.  If that phantom power voltage was wired to your guitar output, it could damage your guitar pickups or electronics.

If you want to save some money, just get a guitar bodypack on the same frequency as the lapel mic bodypack.  That will work great, but you probably will have to call the manufacturer to get the bodypack.