  Galactic nuclei showing recurrent phases of activity and quiescence have
recently been discovered, with recurrence times as short as a few hours to a
day -- known as quasi-periodic X-ray eruption (QPE) sources -- to as long as
hundreds to a thousand days for repeating nuclear transients (RNTs). Here we
present a multi-wavelength overview of Swift J023017.0+283603 (hereafter Swift
J0230+28), a source that exhibits repeating and quasi-periodic X-ray flares
from the nucleus of a previously unremarkable galaxy at $\sim$ 165 Mpc, with a
recurrence time of approximately 22 days, an intermediary timescale between
known RNTs and QPE sources. The source also shows transient radio emission,
likely associated with the X-ray emission. Such recurrent soft X-ray eruptions,
with no accompanying UV/optical emission, are strikingly similar to QPE
sources. However, in addition to having a recurrence time that is $\sim 25$
times longer than the longest-known QPE source, Swift J0230+28's eruptions
exhibit somewhat distinct shapes and temperature evolution than the known QPE
sources. Scenarios involving extreme mass ratio inspirals are favored over disk
instability models. The source reveals an unexplored timescale for repeating
extragalactic transients and highlights the need for a wide-field, time-domain
X-ray mission to explore the parameter space of recurring X-ray transients.
