I once overinflated a Slime self-healing inner tube in my living room. Anyone who has ever seen Ghostbusters will recall the Library scene where green ectoplasm went everywhere. That happened. Green all over our (terrified) white cat, my (irate) wife, the telly and the ceiling. Even two months later we were still finding green splatter in new places .... the underside of our nest of tables, my inkjet printer, the spare TV remote etc. My wife and I agreed I'd do all my bike repairs in the garage in future.
As to actual pressures, I tend to do my rear wheel up to about 90psi, which feels firm but comfortable, and the front wheel to exactly 80psi. I have found that varying it at all on the front wheel distorts the accuracy of my trip computer, which is the old type that uses a magnet on the wheel and is calibrated by reference to the wheel and tyre size.