Is it normal for my ceiling unit to be propped up by wooden boards?

That mess of scrap wood is a classic example of a 'Mickey Mouse' install where someone tried to shim the unit into place without the proper hanging kit or vibration isolation mounts. In older houses, people often just used whatever was on the truck to level an air handler, and it sounds like you've got a DIY hack job using door jambs to create a makeshift support frame. It is absolutely a code violation in most jurisdictions because those units need to be secured with threaded rods or specific mounting brackets that can handle the weight and torque of the motor without shifting over time.

The water dripping from the drywall is a major red flag that the unit has shifted or was never pitched correctly to begin with. These systems rely on gravity to pull condensate into the primary drain pan and out through the PVC pipe. If those wood blocks have settled or warped from moisture, the pan might be tilted away from the drain line, causing water to pool and eventually overflow the internal edges. You also need to check the **condensate line** for a clog; biofilm and algae build up in those pipes and will back the water up into the unit regardless of how level it is. Don't poke around too much if you see exposed wiring near the water. That's a serious safety hazard. You should call a tech to perform a proper static pressure test and re-mount the unit using actual unistrut or hanging straps. They can also install a **secondary float switch** if you don't already have one. That switch will automatically kill power to the AC if the pan fills up, which prevents your ceiling from caving in the next time the drain gets backed up. At this point, the wood is prolly saturated and starting to rot, which only makes the structural support more unstable. Get a pro out there to pull those 'slabs' out and secure the equipment properly before the vibration shakes those makeshift shims loose entirely.

I’ve seen this exact nightmare before. Someone probaly shoved a Goodman or an old Rheem air handler up there and didn't want to spring for a proper 3/8-inch threaded rod setup. Using wood shims is a death sentence for your drain pan's pitch. If it’s tilted even a fraction of an inch the wrong way, you’re looking at a rusted-out primary pan in no time. You need to verify if there’s an SS2 ceiling switch installed. If that DIY installer skipped the mounting hardware, they definately skipped the safety overflow switch. Get a pro to swap those blocks for some actual Unistrut and a set of vibration isolation pads before that motor shakes the whole mess trough your ceiling.

Are we sure the water is coming from the unit itself? Everyone’s jumping on the 'hack job' bandwagon becasue the wood looks ugly, but have you ruled out a roof leak or a sweaty plenum? If that wood is dry to the touch except for where the water's dripping, it might just be condensation forming on the outside of the cabinet because the insulation is thin or missing. Before you pay someone to rebuild the entire frame, I'd check if the ductwork is properly sealed. If humid attic air is hitting the cold metal of the unit, it’ll drip regardless of how level it is. Have you acutally touched the wood to see if it's saturated?

Quick update—I checked the wood supports like someone suggested and they're dry near the top, so I’ve ruled out a roof leak. But the drain pan is definately pooling because the pitch is off from those wood shims. I’m still seeing water at the drywall edge. If I try to install a proper threaded rod setup, do I need to brace the unit from below first?