Hi,
There are many suitable switches, but be sure to get one rated for low current. High power appliance switches sometimes need the high current to keep the contacts clean and can fail when used on low DC current.
That is true. The Honeywell switch I linked to has silver contacts and would ideally be switching rather more current
than the gold contact one MN300 linked to. Having said that I have used these Honeywell switches (Omron make identical units)
for years at low currents without difficulty.
As MN300 comments there are any amount of switches that would work. I think however that plenty of overtravel is
the critical characteristic rather than switch current.
Either way the simple idea of a spindle mounted carrier should enable OP to make a probe for way less than buying one.
Craig