  We examine data from the Murchison Widefield Array (MWA) in the frequency
range 72 -- 102 MHz for a field-of-view that serendipitously contained the
interstellar object 'Oumuamua on 2017 November 28. Observations took place with
time resolution of 0.5 s and frequency resolution of 10 kHz. %This observation
was undertaken for another purpose but due to the MWA's extremely large
field-of-view, 'Oumuamua was serendipitously observed simultaneously. Based on
the interesting but highly unlikely suggestion that 'Oumuamua is an
interstellar spacecraft, due to some unusual orbital and morphological
characteristics, we examine our data for signals that might indicate the
presence of intelligent life associated with 'Oumuamua. We searched our radio
data for: 1) impulsive narrow-band signals; 2) persistent narrow-band signals;
and 3) impulsive broadband signals. We found no such signals with
non-terrestrial origins and make estimates of the upper limits on Equivalent
Isotropic Radiated Power (EIRP) for these three cases of approximately 7 kW,
840 W, and 100 kW, respectively. These transmitter powers are well within the
capabilities of human technologies, and are therefore plausible for alien
civilizations. While the chances of positive detection in any given Search for
Extraterrestrial Intelligence (SETI) experiment are vanishingly small, the
characteristics of new generation telescopes such as the MWA (and in the
future, the Square Kilometre Array) make certain classes of SETI experiment
easy, or even a trivial by-product of astrophysical observations. This means
that the future costs of SETI experiments are very low, allowing large target
lists to partially balance the low probability of a positive detection.
