Unfortunately vacation can't last forever but you can help recapture the magic by listening to the music at home. There are numerous ways to do this.
At one time finding Disney park music online was extremely difficult but no longer. These days there are literally more sources for park audio than you can count. If you are sitting in front of your computer simply go to Live365.com to start. Search for Disney music and you'll see more stations available than you'll have time to listen to. Don't want to sign up for Live365 (even the free option)? Then you've still got a number of terrific websites dedicated to Disney audio.
MouseWorldRadio.com is usually my first stop. It's been going for 10 years now and there are now (I believe) 5 different channels all playing high quality Disney park audio. Another great option is Sorcerer Radio. It's been around for a long time as well and has a great variety of music. A few others to try out: Studios Central Radio - dedicated to Hollywood Studios music, Subsonic Radio - a multi-channel Disney music source, & D-Cot - a free community where users share their Disney music. This is just scratching the surface, but these stations alone are a great start to finding music at home.
If you're on the go there are many apps for you iPhone, iPad, Android that can keep you streaming away from home. MouseWorldRadio, Subsonic, & Studios Central Radio all have excellent apps available for free and there's also Shoutcast, LastFM, and Pandora. These aren't specifically apps for Disney audio but searching their channels will get you lots of Disney music options.
There may come a time when you want to collect music for yourself rather than stream it. I totally understand that desire to own it for yourself but be aware Disney has been...stingy with the content it's made available. Of course there's the numerous CDs of audio sold at the theme parks, and I highly recommend them, but when you consider the hours and hours of music played throughout their parks it seems as if Disney is missing out on a gold mine. If they packaged and sold their entire catalog of music they'd be...well even more rich. However, I'd be broke so maybe its for the best.
Check iTunes, Amazon, eBay and you will occasionally find other park music for purchase. Otherwise, your best bet is Google and/or Youtube. Anything can be found on Google but there is a question of legality. You can find music available for download but if it's available for free it's likely illegal. I avoid these sites and instead head to Youtube. Type in Haunted Mansion and not only will you find uploads featuring attraction audio but often you get to go for a virtual ride as well.
One last link I strongly recommend if you are intent, (like me), on collecting park audio. Parktunes is a wonderful website created by the prolific Ricky Brigante, the guy behind the terrific Inside the Magic podcast. Parktunes is an exhaustive listing of the audio available at all the parks with purchase links if that music is commercially available.
Hopefully this list of sources gets you started on the right path whether you are looking for streaming music or a home collection. Believe me you'll never find it all, but what a great way to recapture the Disney magic at home!