On Fri, 9 Dec 2016 06:10:39 -0800 (PST), John G
wrote:

I would like to connect a sauna heater in my garage. It is a 240v 23amp
heater. This picture is my box. Will it work?
http://www.homeownershub.com/img/81
http://www.homeownershub.com/img/82

You would need at least a 30 amp feed to that existing fuse box. I cannot tell what size wire is there from your photos, but something doesn't seem right. You may only have 120 volts there and no ground. I suggest that you have an electrician in to give you an estimate of what it would cost to connect a sauna.

John Grabowski
http;//www.MrElectrician.TV

This is the right answer