Langstaff and Sloan | 50 followers on LinkedIn. Since 1991 we have provided professional electrical contracting services in the GTA. | ELECTRICAL CONTRACTOR AND ELECTRICIAN Since 1991 we have provided professional electrical contracting services in the GTA. Our core business remains Residential Service with our specialty being Knob and Tube rewiring. We also have extensive experience with high rise Sub Metering, retrofit lighting, renovation type construction for commercial leasehold improvement and multiple Utility/OPA sponsored programs such as Peak Saver.