How can I replace the on/off switch on a whirlpool tub that is in an alcove and does not have any access panels. Thanks

I have seen people cut the switch out and then use a decorative escutcheon to cover the hole and place the switch in the escutcheon.

If the tub sits on raised foundation, crawl under the house, drill hole in the floor and reach the button that way. If the tub is on 2nd floor, access it through ceiling below.

Tub should have some kind of access panel as somebody had to connect it with the drain, after the tub was set in the pedestal. Look under the house, behind the wall in the closet, etc.

Milo