PuZzLe [ENDED] [Solution Posted]

pUZzlepUzZLepuZZlEpuzZLepUzZLepUzZlepUzz
pUZzLEPUzZLepUzzlEpUZzlEpuZZlEPuzZLepUzZ
pUZZLePuzZLEpUZZlEPuzzLepuZZlEPuzZlEpUZZ
pUzzLEPuzZLEPuZzlEPuzZlepUzZLePuzZlEpUzZ
pUZZLepuzZlePUzzlEPUzzLEpUZzlEPUzZlEPuzz

SOLUTION:

There were five giveaways. Each row contained one giveaway code.

Each row represents a string of binary numbers, zeroes and ones. The lower-case letters are 0 and the upper-case letters are 1. (the actual letter itself being P or Z or whatever is irrelevant)

So, for example, the first one converted to a binary string would become:

pUZzlepUzZLepuZZlEpuzZLepUzZLepUzZlepUzz
0110000101100011010001100101100101000100

The binary string actually represents a series of ASCII characters, 8 bits per character:

01100001 01100011 01000110 01011001 01000100
97 = a   99 = c   70 = F   89 = Y   68 = D

put them together you get acFYD which is the giveaway code. Add it into a giveaway URL and you get the link to the GA:
https://www.steamgifts.com/giveaway/acFYD/

The hints with Homer flipping the light switch represent binary (off and on), the cats lookup and and down are a hint to look at the upper-case and lower-case, and the (very old) ASCII table is a very direct clue that you need to convert binary to ASCII :)

that's it :)