Everyday house and job-site debris is fine. The limits come from state rules and from what the receiving station will take off the truck.
Washington keeps mercury out of the ground. The state environmental agency is direct about it: landfills cannot accept mercury-containing lamps or other mercury-containing items. That covers fluorescent tubes, compact fluorescent bulbs, and old thermostats, and the tubes must not be crushed. Set them aside for a collection point.
Paint, electronics, and household chemicals are out too. Lakewood's own guidance is that paint, electronics, and hazardous materials have to go to a transfer station or a special waste location rather than in the garbage, and there are free drop-off sites around the county for leftover paint.
The usual exclusions apply as well: solvents, fuel, motor oil, antifreeze, pool chemicals, propane tanks, car batteries, and anything containing asbestos. Liquids are a problem on their own, since a leaking container can be turned away at the scale.
Not sure where an odd item belongs? Ask your account manager before it goes in the container.