Question

we finally found the fire extinguisher we had been hunting for behind a pile of logs

Answer 1

Were you hunting behind a pile of logs? --

or

Was the fire extinguisher behind a pile of logs?

We can't tell from this sentence.

Answer 2

Had "we" been hunting for the fire extinguisher behind the pile of logs? Or did "we" find it behind the pile of logs?

http://grammar.ccc.commnet.edu/grammar/sentences.htm#modifier_placement
and
http://grammar.ccc.commnet.edu/grammar/modifiers.htm#misplaced

Answer 3

i don't understand

Answer 4

What part of our explanations don't you understand.

We both showed you the misplaced modifier.

Answer 5

Modifiers (adjectives and adjective phrases mostly) need to be placed as close as possible to whatever they're describing/modifying.

Which one, do you think, is the corrected version of what you posted?

~~> We had been hunting for the fire extinguisher behind a pile of logs, and we finally found it.

~~> We had been hunting for the fire extinguisher, and we finally found it behind a pile of logs.