Plastic and Metal Mystery with Wheel and Spring

This item was left bagged up under the sink by someone who helped clean my house. Not sure if it broke off of something or was accidentally removed from its proper home. I’ve checked the laundry equipment and dishwasher and did not see any missing pieces. It is light and has the numbers 2-2 stamped on it. There is a small plastic wheel on the bottom and the metal spring is on top. Thanks in advance for any assistance.