Had a strange one today..

While squawking IDENT , our "ident" stuck "on"

ATC confirmed we were continuously "identing"

Cycling the transponder to off then on again cleared the
ident fault.

Pressing the button again locks the ident light on again
until the power is cycled..

Any thoughts?

Switch appears mechanically OK, (clicks when pressed, clicks
when released)..

It is a King KT78 "KT76TSO"

Dave