Spurious interurupt - what is it?

[wilber at alice.UUCP]

What does

    Spurious interrupt - level 2

in the unix.log file mean?  I've been getting lots of these.

Bob Wilber   Work: UUCP: {allegra, mtune, ihnp4}!gauss!wilber
                   ARPA: wilber at research.att.com
             Home: UUCP: {allegra, mtune, ihnp4}!gauss!heaven!wilber
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