I would like to get rid of a dishwasher. I’m down to the wiring. Should I simply (after turning the breaker off) take the wire nuts off the existing wiring, untwist any wires that are twisted and then place nuts back on each individual wire (meaning the wiring from the house not the dishwasher)? I was thinking about doing that and then wrapping electrical tape around the nut down to the wire so that there won’t be any opening on the underside of the nut. Then I was thinking about taping the cable wire to the wall or stuff it back from which it came. Does this seem like the way to go about this?

When I did mine I followed it back to the junction box and disconnected it there. If you have a dedicated box then I would wire nut the ends and wrap a generous amount of electrical tape around each one to make sure that they are moisture tight. Make sure the power is off.

you should not put wire ends inside a wall with out a accessible junction box. Is the dishwasher on it’s own breaker? if it is, I would disconnect the line from the breaker, then wire nut the wires on the dishwasher end together, that way no one will be able to make that line live simply by flipping a breaker. If the dishwasher is not on a separate circuit, then I would put a junction box in the wall, wire nut the wires individually, and put a cover on the box. That way it will still be available if you decide to put another appliance back in.

I’m not sure where the cable leads to but I think I’m going to investigate further now. You mentioned junction boxes. Great idea, thank you. I think there are metal and plastic boxes available for sale. This wire is currently under a kitchen counter where a dishwasher used to be. I imagine it would be much better and safer to place the existing wire in one of those boxes and mount that on the underside of the counter or towards the back of the area in which the dishwasher once sat. Great idea, thank you for that. Better than my current solution of hooking the cable to the wall.

Normally I would not answer this sort of a question because of code issues, but I am pretty sure this one is constant all across North America: all splices and terminations must be inside a properly secured properly rated junction box with a secure cover.