Could you use "je suis pressé(e) de..." for "I can't wait to...". i.e. Je suis pressé(e) de découvrir le manoir hanté...
I thought I had seen that construction suggested as a possibility somewhere in the past, but I'm never quite sure if it rings correctly to a native speaker, or if that sounds more like "I'm in a hurry to..." (i.e. more stressed than excited).