Electricians specialize in electrical wiring of buildings, stationary machines, and related equipment. They can either be employed to install new electrical components or for the maintenance and repair of existing electrical infrastructure. Electricians may specialize in wiring ships, airplanes, as well as data and cable. The electrician’s working conditions vary by specialization and is generally physically demanding. Occasionally an electrician must work in a cramped space or on scaffolding. Service electricians respond to requests for isolated repairs and upgrades. They troubleshoot wiring problems, install wiring and make repairs to wiring in existing buildings. Construction electricians primarily focus on larger projects, such as installing an all new electrical system for an entire building, or upgrading an entire floor of an office building.