Autodesk Collaboration Solutions Engineer, Jason Pratt, provides a set of electrical symbols to his customers.
Download Electrical Symbols ZIP file (468KB).
The files (symbols-8.dwf and symbols-4.dwf) are electrical symbol libraries in 1/4" scale and 1/8" scale that you can load into Autodesk Design Review (formerly known as Autodesk DWF Composer). The DWF files contain typical electrical symbols like outlets, switches, ceiling fans, light fixtures, etc.
Jason notes that the best practice is to break the symbol libraries down into smaller sets, so they work better on the symbol library pull down. Jason has done this with the 1/8th scale but not the 1/4th scale library. (outlets-8, fixtures-8, special-8, switches-8 - load each individually.)