Ron in CA wrote:
The other day I noticed our porch light was out. Assumed it was the
bulb, but that wasn't it, so I removed the fixture, thinking it was a
loose wire nut. There is a black wire and a white wire in the box. Turns
out, the black wire is severed near the back of the box, with
just a piece of insulation holding it to the wire that would connect
to the fixture wire.
Is there any way to splice the wire when there is just a quarter to
half-inch to work with inside the box? Otherwise, it looks like I'll
need an electrician to go into the wall. Any advice is appreciated.

Have you tried grabbing the stub with a pair of needle-nose pliers and
tugging it? A professional installation usually leaves ample slack in the
wire for just such contingencies.