They are indeed mushrooms of some kind - can't tell what for sure from the picture. They aren't harmful to the plant but are easily removed it you want to. Spores must have got into the compost, probably on the woody material, and you may get another crop later. You can repot in clean orchid compost if wished.

I agree with Steragram's last point - It's time to repot. Mushrooms feed on dead plant matter. When you repot, rinse the roots under cold running water for a few minutes to remove any salt build up from fertilizers. Give it a new pot, with new plant medium.

It may also have been slightly overwatered--the exposed roots look none too healthy.

They will be growing from the bark in the orchid compost. They do no harm at all and, personally, I would leave them as an 'added interest'.

The mushrooms themselves aren't doing any harm, but they may be a symptom of overwatering, or insufficient drainage.

Thank you. I probably have over watered it. Thought it might need extra as the flowers are in full bloom.

Phalaenopsis do best with regular, but not too frequent, watering over their life cycle. They also don't like to sit in water.

Phaleanopsis are epiphytes, and like their roots exposed to air. I think you have the roots buried too much which is causing them to die, hence the mushrooms. Let the roots 'climb' out of the pot. You can simply mist them a couple times per week.