You'd be surprised how tricky this can be. Pure slapstick in novel form is actually pretty rare—it's a physical, visual comedy style, so translating it to prose without feeling forced is a real skill. I tend to find the best 'lighthearted reading' with that chaotic energy comes from authors who weave slapstick moments into a larger comedy of manners or a farcical plot.
Terry Pratchett is the undisputed master for me. His books, like 'Guards! Guards!' or 'Going Postal,' are packed with that perfect, character-driven physical comedy. The humor comes from people's sheer ridiculousness in a grounded way, like a city watchman accidentally arresting himself. It never feels cheap.
For something more modern and unabashedly silly, I had a blast with 'Kings of the Wyld' by Nicholas Eames. It's a fantasy romp about a washed-up band of mercenaries getting the gang back together. The action scenes are hysterically over-the-top, with a definite Three Stooges vibe as these old guys fumble through their quest. It's loud, joyous, and doesn't take itself seriously for a second.
Honestly, I'd also check out some of the classic P.G. Wodehouse Jeeves and Wooster stories. While more verbal wit, the situations Bertie gets into are pure farce—hiding cow creamers, dodging aunts, getting trapped in steamer trunks. The physical comedy is in the elegant panic of it all. That's my personal holy trinity for a guaranteed laugh.