sure, i build mine out of rough grade pine decking. 1x10`s i make them 24 inches long. you will need to nail the sides of the box to the top and bottom, so when ya mesure across the top of the finished box its 11 inches, not 9 and a 1/2. also, i only put a 12 inch peace in the bottom so the front 1/2 of the box has no bottom. i feel it gives the coon more confidence about entering the box. also you can tip the box up and change out bait without taking the trap out of the notches.
about the notches, this box is for the 220 conie. after you build the box just set a 220 and hold it up to the box to see where to cut the notches, make them alittle big. mine are an inch and 1/2. and 4 inches deep, use a jig saw. now, behind the notches about 3 inches nail a 3/4 inch roofing tack and leave about 1/4 sticking out. this is for a 6 inch piece of 14 gauge wire, wire it to the tack. then you have something to wire the back part of your trap spring with to keep coon from flipping your trap out.
the most inportant part of the box is the back. use 1/4 inch hardware wire, that way the coon can see through it.
i use fresh, or fresh frozen catfish scraps and alot of it....matt
also i paint mine with cheap flat black paint, and its best to set a log or a rock on top of it. i set alot of them on big flat rocks on rocky banks. its places like this that really shine, other trappers just drive on by becouse ya cant set a paw catch trap there. set them as close to the waters edge as you can and still hide them from pasers by. if you must set them on up the bank alittle, use a fish oil trailing scent from the water to your trap.