dumb question about paneling

[Donny Random]

I am have the electric service updated and the fuse box that is in the kitchen is being moved to the outside. Now I will have a hole where the box was in a wood panel wall. What is the best way to repair this hole to make it less conspicuous that there was a hole there? The obvious choice is to use similar paneling cut to size, but how to keep it in place in the hole?