For a straightforward installation of a single standard box in an accessible location, homeowners often see $120-$260. Projects involving new or upgraded circuits, larger panels, or difficult access commonly run $800-$1,600, with high-end setups surpassing $3,000 in some. Homeowners typically pay a broad range for electrical box installation, driven by box type, wiring complexity, and local labor rates. Cost and price details focus on realistic estimates. How Much Does It Cost to Replace An Elec. Electrical service costs depend on your project and location. Check with a local pro for your specific job. Plastic junction boxes for indoor wiring cost 50% to 80% less than metal boxes but aren't as durable. Cost. On average, the cost of rewiring a 1500 sq.