wrote:
Hi,

What's the best way to patch this hole.

http://i.math.drexel.edu/~pg/howtopatch.jpg

The vanity in front of the wall (you can see that backsplash on the
picture) cannot be moved as it is calked to the floor.

Many thanks in advance!

Aaron Fude

It looks like there's a stud to the left of the box. If so then do
the following.


Remove the outlet

Widen the hole so it exposes half of the left stud and cut the top of
the hole back to expose a few more inches above the outlet box.

Cut a square patch that fits as accurately as you can.

Put a little chalk on the box and push the patch into the hole
transferring a chalk outline of the box opening onto the back of it.

Using a small keyhole saw or utility knife, very carefully cut the box
opening in the patch.

Glue the patch to the studs, tape, and mud the seams. Sand, prime, and
paint

Put the outlet back on.

As for the vanity splash, I would attempt to have the patch dip under
it by a few inches and glue it in place. Use caulk to hide any
imperfections.