If you have a home gym check your rack once in a while.

How often do you wipe down your equipment/bumper plates?

When I was a graduate teaching assistant I taught a weight training class. I used to tell the students to check the equipment. It's a big deal. At my local gym I started putting a multitool in my bag. The other day I tightened one of the arms on a plate tree. It had come so loose that the plates were beginning to slide off any time the thing was touched.