There are all the drawings from Bobs Aeroelectric book in ACAD format.
The drawings have symbols on the face of the drawing of course but there are libraries of blocks nested in the background too.
If you read his book, you may find that there is one of the architecture drawings that you like. It is easy to start there and modify.
They are scaled for 11 x 17 paper and are readable on letter size, but I've just discovered my HP printer has been declared obsolete and HP quit making cartridges for it... bummer it's only 15 years old...
IIRC TurboCAD imported the AutoCAD symbols OK, but lost the reference points.
To draw schematics easily you need a good grid and all of the lines and symbols to accurately "snap to grid"...
My sheet above shows 0.25 grid, but I later changed it to a 0.2 inch grid to get more on top a single sheet. If you go any smaller you probably have trouble reading a letter size printout.
Dang, rzbill! That's some useful info. And here I thought I'd have to start with a Cessna 150 wiring diagram and modify it for my needs. Thanks for turning me on to this site, and Bob Nuckoll's book!