This is electrical wiring junction box information post with questions and answers. There are many types and many uses for j-boxes but choosing correct one always depends on what use is needed. The 4in. sq. metal box can be used both residential and commercial. The single-gang cut-in is the best for brick. If you have any questions register then come back to this page to ask your question using the comment section at bottom of page. Thanks
single-gang metal cut-in box
4in sq metal box – can be used flush or surface mount.
Not flush mounted, plaster ring not flush with brick.
Plastic-nail-on can be used in brick but not recommended.