[header] How to prevent electrical accidents with hand tools [title] Never use any electrical hand tool that does not carry the underwriters laboratories seal of approval. [substeps] This seal indicates the tool has undergone extensive testing and has been found to be safe when properly maintained. [title] Older tools with a two-wire design should be immediately upgraded to a three-wire system by qualified personnel. 
[substeps] If your tool cannot be upgraded, discard it. Most power tools in use today have a three-wire system.