Hi, so about two weeks ago I started noticing this weird green stalk growing off of my cactus. At first it was short and I thought it would just become a new leaf on my cactus. But it just keeps growing. I have no idea what it could be, but it seems to be healthy otherwise. Thanks

It is a new leaf. Your cactus is not getting enough light so the new growth will be pencil thin. There's nothing you can do for that leaf - it will be forever skinny. Find a spot with lots of sun or get it outside.

Hi, thank you so much. I will definitely move it to another spot. Should I just chop it off? And if so will it ever grow another leaf?

Yes, you can chop it off. And yes, it will grow another leaf. In fact, if its getting sufficient light, it will grow several new leaves each year... and bloom.

But... BIG but... introduce it to more sun gradually or it will sunburn. From your house to outdoor total shade, to dappled shade to full sun. This transition could take a couple weeks.