How to secure gun but stay ready for defense

[Diggles]

Anyone have any suggestions on how go about doing this? I dont much about safety in this aspect. The only thing I've really seen is a trigger guard lock, which requires a key...which you'd be fumbling for around in the dark, or worse, not able to remember or have to run TOWARD the door to get...not ideal.

Bottomline: I have a loaded revolver for home/self-defense and dont want GF or maintenance person in my house accidentally setting it off, but I want it to be ready if its needed within 5 seconds.