  The JWST North Ecliptic Pole (NEP) Time Domain Field (TDF) is a $>$14 arcmin
diameter field optimized for multi-wavelength time-domain science with JWST. It
has been observed across the electromagnetic spectrum both from the ground and
from space, including with the Hubble Space Telescope (HST). As part of HST
observations over 3 cycles (the "TREASUREHUNT" program), deep images were
obtained with ACS/WFC in F435W and F606W that cover almost the entire JWST NEP
TDF. Many of the individual pointings of these programs partially overlap,
allowing an initial assessment of the potential of this field for time-domain
science with HST and JWST. The cumulative area of overlapping pointings is ~88
arcmin$^2$, with time intervals between individual epochs that range between 1
day and 4$+$ years. To a depth of $m_{AB}$ $\simeq$ 29.5 mag (F606W), we
present the discovery of 12 transients and 190 variable candidates. For the
variable candidates, we demonstrate that Gaussian statistics are applicable,
and estimate that ~80 are false positives. The majority of the transients will
be supernovae, although at least two are likely quasars. Most variable
candidates are AGN, where we find 0.42% of the general $z$ $<$ 6 field galaxy
population to vary at the $~3\sigma$ level. Based on a 5-year timeframe, this
translates into a random supernova areal density of up to ~0.07 transients per
arcmin$^2$ (~245 deg$^{-2}$) per epoch, and a variable AGN areal density of
~1.25 variables per arcmin$^2$ (~4500 deg$^{-2}$) to these depths.
