The last two weeks I have been coming out to my brake lights on/dead battery

What is your question?

I began doing circle checks of my car before I went inside every night. All lights would be off when I go inside, yet I could come out 5 hours later and the brake lights would be on. Or in the morning my battery would be dead. Tonight I caught the lights on, I sat in the car and fiddled the brake pedal. At full depression the lights were on (good). At 1/4 inch depression the lights were off (okay). When left unpressed, the brake lights were still on (very bad). 1) What could cause this? 2) How can I fix this without spending a bunch of money at a shop?