- Mines and bombs given fire, spectral fire, or shock could apply that status when they explode
- A minecart on fire could deal constant damage while you're in it
- Shock bumpers could bounce you and prevent you from reacting in time to do something else
- Shock on Water Pipes could electrocute the player
- Items with a property could inflict them when picking them up
- Sword with properties could give the player's sword the ability to inflict that status
there's lots more that could make some sense, and some that don't really make sense. Swinging your sword at a shock skull could stun you, but swinging at a burning skull doesn't really seem like the flames ought to travel up your sword... but for the sake of consistency, it's not entirely awful to have it work that way.