Re: 1995 150 Evinrude- Anode inside the gearcase
I wouldn't mess with that anode unless you need to reseal your gearcase.
Take a test light, hook it up to the + side of the battery, and then poke all of your engine anodes with the test light, if the light comes on your anodes are properly grounded and you are good to go. Keep all of your easily accessible anodes in good condition and you'll be good to go.
If the light does not come on, then your anodes are not properly grounded and will not work properly. You need to check and find where it lost its ground and repair it, otherwise even with a new anode they will not work properly.