Grimrock

I'm stuck in the Mausoleum section. I defeated all the enemies and the leprechaun disappeared. There are no hints that I can find to solve the puzzle. There is a room with a locked gate door and a floor panel with "lightning squares" flickering on and off on the opposite side of a gated wall to the right. There is also a floor panel back where the leprechaun was when I first entered the area. I've tried all combinations of floor panel pressing and holding, moving to the rhythm of the "lightning squares" and I've checked all walls for switches/buttons and can't find any. Been stuck here for a couple hours. Anyone get through this part or able to provide a tip/hint?

Look at the floor below the force fields, there's a pressure switch you can drop something on. That will open a grate to another pressure switch. That pressure switch is covered by a force field. The switch directly in front of it on ground level toggles that force field off for a short period of time, you need to time turning off that force field and throwing an item at the switch so that the item isn't blocked by a force field. It may take a few tries.