An energetic, vibrant person: Jimmy's a live wire, all right(1909+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with live wire
A highly alert or energetic person. For example, Sally's a real live wire; she brightens up any gathering. This metaphoric term transfers a wire carrying electric current to a lively individual.
[ c. 1900