Conduit is required for running electrical wire on a brick wall. Usually some of the conduit will have to be bent for it to fit flat against the wall. Bending conduit is a skill that has to be developed and will be the hardest part of this job. It is assumed that the wire is being installed either for an outside light or receptacle and will be run vertically down the wall from the attic.
Drill a 1/2 inch hole in the soffit of the house where you want to bring the electrical cable from the attic. Drill the hole as close to the fascia as possible.
Ream the hole enough to allow the conduit to fit snugly. Push one end of the conduit through the hole and leave it flush. Measure the amount of bends needed to position the conduit against the wall.
Remove the conduit from the soffit and bend it with a conduit bender to the desired shape. Several tries may be necessary before the conduit is bent correctly.
Cut the conduit to the required length with a hacksaw or pipe cutter and thread the cable from the attic through the conduit. Slip a conduit connector over the cable and attach it to the end of the conduit. Attach an outlet box to the connector and tighten the locknut with a hammer and screw driver. Leave the cable hanging out of the box.
Position the outlet box and conduit against the wall and mark the screw holes on the wall with a pencil. Place enough conduit straps at intervals along the conduit to hold it securely to the wall. Mark the holes in the straps on the wall with the pencil; move the conduit, outlet box and straps to one side.
Drill the marked holes with a masonry drill and insert plastic wall anchors. Secure the outlet box and conduit straps by putting screws in the wall anchors. Putty or seal any open space where the conduit goes through the soffit.
Check with your city electrical inspector. You may be able to use EMT conduit, which is easier to cut and bend.
Do not work with previously installed wiring until the power is turned off.