<<Being concerned about a runaway trim, I installed an on/off switch in line
on the hot lead.  The switch is installed in front of the stick on the lower
edge of the instrument panel and appropriately labeled.  The switch is
normally off but when I want to use the trim I turn the switch on, make the
adjustment then turn the switch off.  This avoids possible runaways from a
short and or an immediate cutoff in event of a runaway.  Thus trimming is a
two hand operation, one for the stick and trim button, the other hand on the
on/off switch.>>

My 182 had an S-Tec 60-2 with an interesting solution to the problem  - and
one that I intend to incorporate in my ES.  Instead of using a DPDT switch
for pitch trim they used two SPDT switches with the paddles side-by side,
the paddles being shaped such that they felt like one paddle.  You had to
push both switch simultaneously to get trim movement - one switch could fail
closed and the trim would still stop when released.  If one switch shorted
in one position when the switches were moved to the other direction the
resulting short would pop the breaker.

Gary Casey