John K Jordan
I've "refurbished" a lot of equipment switches over the years. Most just require cleaning but if sticking I disassemble completely and lubricate all the moving parts. Examine the mechanical mechanism for signs of wear or a broken part and repair as needed. Some require drilling out rivets to get apart.
After cleaning the contacts (1500 grit paper is good, don't remove any plating) I apply a tiny smear of dielectric grease to each contact surface. Depending on the switch I might lube the moving parts with dry lube or silicon grease. After testing, if the switch is subject to gumming up with fine dust (like the Jet 1642 switch) I seal the outside from dust with plastic wrap, tape, sealer, whatever fits best.
You forgot to say what a LS 1211 is but since it is in a handle is a clue. If the switch is a microswitch engaged by a trigger mechanism, replacements are readily available. Even a non-standard microswitch can usually be replaced with one off the shelf with some mounting ingenuity as long as the current rating is ok. The mfgr may even have an inexpensive direct replacement. But if the microswitch itself checks out a non-release problem is probably wear in the trigger, levers or ratchets that engage the switch. Hard to say without inspection.