chaz wrote:
I have a bright yellow fungus, tall slim with a cap, that keeps
appearing in my inside cactus display, anyone know how I can
identify
it?

Your local Wildlife Trust will have a mushroom expert..
Publish a photograph?
Do a Google image search for yellow mushrooms.

Are you growing your cactus in leaf litter?
Fungi thrive in moist conditions, cacti in dry(ish). Somethings not
right.

--
ned