"From what I understand now it is not code to drywall over a spliced location. Are there any exceptions? "

There are no exceptions.
All junction boxes must be accessible.

Accessible is defined as not requiring damage to a finished surface to gain access.

The box should have been left with a blank cover plate.

"Would you guys leave it as is or would you recommend I cut off the wire at the attic location, add a junction box in the attic and re-run the wires to the new switch location through the wall? I would have to leave the old disconnected wire and box buried in the wall."

This is fine and code compliant as long as you are SURE the box is completely dead.

There is no requirement to actually remove decommissioned cables or boxes.

You should never let these fools into your house again and should report them.

Their next 'customer' may have no idea.

Thanks... Sounds like you are saying I should fix it.
Its an easy fix so I am going to do it. I will sleep a little better at night.
Is it a stupid code or is it a fire hazard?

Does the junction box in the attic need any space away from insulation?

It is not a stupid code. Cables don't fail. However connections do fail. If the junction box is buried inside a wall there is no way to fix a connection if it fails without smashing out the drywall. Of course you need to know the junction was there to even go look for it.

Fix it.

"Does the junction box in the attic need any space away from insulation?"

No. Insulation is not a finished surface.
If enough power is dissipated in a junction it needs cooling something is seriously wrong.

If the junction box is buried inside a wall there is no way to fix a connection if it fails without smashing out the drywall.

When demolishing older homes--pre-1940s--I would notice great clots of wires wrapped in tape at certain points behind the walls. Don't know if that was standard practice of the time, or just bad practice. Imagine trying to trouble shoot a dead circuit with that arrangement!

I wouldn't say that "great clots of wires" were the norm, but in the days of knob and tube, not all splicing was done in j-boxes by any means. Pigtails to devices were often spliced to the wires at a knob. In some cases they were then connnected to the devices without any boxes at all - just a length of loom on each for additional protection. This was typical for a ceiling light fixture, for example, where the fixture canopy was the box, screwed right to the ceiling surface.

All this sounds riskier than modern practice, and I don't doubt that it was. But there were a couple of mitigating factors.

First, the kinds of loads we routinely see today were just about unheard of. Many times a room would be lit by a single 40 or 60 watt incandescent bulb (it sure beat the light of a gas lamp!). About the only large appliance you'd find regularly in those early days would be a flatiron (though space heaters and toasters seem to have caught on fast). So loads were much lower. Many homes were wired with just four 15-amp general purpose circuits, and maybe an electric range receptacle.

Second, those splices were soldered and taped with insulation equivalent to the wire's (meaning a layer of rubber tape and a layer of cloth friction tape). Solder is great stuff, when properly applied to a mechanically solid connection. It reinforces the splice and seals it against oxidation.

The techniques of the K&T days were pretty good ones, certainly for the needs of the time. Also, my impression has been that most of that wiring was done by pros (though I live in a house where the original K&T was either DIY or done by a VERY careless pro). It's too bad that the rubber insulation used in old K&T has rotted from age, heat, and the gunk we've put in our air over the years.

Revisiting this old topic....

I chose the location for all of my switches and outlets in the new house. For the most part they're fine, but there a couple where I'm left scratching my head and wondering what I could have been thinking. I'd like to move them but considering my reasons for doing so involve clearing the wall so I can hang some mirrors and art, putting a blank plate over them doesn't really solve the problem. Also, I find those blank plates rather unsightly. I would love to drywall over them, but I understand this is neither wise nor encouraged.

So is there no other option? It seems to me if you were remodeling you would be moving switches and outlets all the time and I know remodeled homes don't have random blank plates all over the wall. Surely there is a way to move this stuff and still have an attractive wall?

Thanks!

Surely there is a way to move this stuff and still have an attractive wall?

Sure - you run new wires.

If you don't want to do that then hang a mirror or some art over the blank plates!

K&T (spliced or not) should not be buried in insulation. It's only rated for free air. K&T is not really a safety issue until someone either mucks with it inappropriately or retrofits insulation, etc... over the top of it.