You can buy liquid tape for insulating electrical wire splices, or you can make your own. Oogoo is an excellent electrical insulator.
You can mix up a standard mix and add solvent to allow it to be painted on thinly. This works fine.
If you want to make it more fire retardant and heat resistant, you can add red iron oxide. A mix of 2 red iron oxide to 2 silicone caulk to 1 corn starch works well. Add enough solvent to thin as desired.