Wire Fraud is prosecuted under 18 U.S.C. § 1343.  It is essentially the same crime as Mail Fraud, which is prosecuted under 18 U.S.C. § 1341.  The only real difference between the two crimes is the communications method.  The actual language of section 1343 is:

Whoever, having devised or intending to devise any scheme or artifice to defraud, or for obtaining money or property by means of false or fraudulent pretenses, representations, or promises, transmits or causes to be transmitted by means of wire, radio, or television communication in interstate or foreign commerce, any writings, signs, signals, pictures, or sounds for the purpose of executing such scheme or artifice, shall be fined under this title or imprisoned not more than 20 years, or both. If the violation affects a financial institution, such person shall be fined not more than $1,000,000 or imprisoned not more than 30 years, or both.

As you can see, the language is convoluted and it doesn't really tell an individual--who is presumed to know the law, after all--anything.  Depending on in which jurisdiction the case is brought, section 1343 is saying:

It is a crime punishable by up to twenty or thirty years of imprisonment (depending on circumstances) for a person to:

• Develop (or intend to develop) a plan to
  • defraud; or
  • get money by false or fraudulent methods; and
• Use interstate telecommunications to carry out that plan.

The devil, of course, is in the details:  what's a plan to defraud? what are false and fraudulent methods? what does it mean to use telecommunications? what does it matter where the case is brought? what's the likely sentence for a conviction?  That's why it is especially important for an individual facing federal wire fraud charges to speak with a lawyer deeply familiar with federal criminal defense.