To get professional-looking splices in wiring without electrical tape, try head-shrinkable tubing. Slip a tube on one of the wires before splicing. After splicing, move it over the splice and apply heat with a heat gun. The tubing will shrink down for a neat, protective covering. You can buy tubes in multiple sizes, as well as shrinkable wire caps to use in place of screw-on wire nuts. They're perfect for work on vehicles, trailers, underground and pool wiring, or for outdoor lighting or sprinkler systems.
Plumbing stacks may run inside the walls of your home, from the basement to the attic, with openings at each floor where the pipes branch off. Use the piping runs in the basement to help you locate holes. Plug the bottom and top of the chase with foam caulk or 6ml polyethylene.