Scales to Play Over Fm7b5
Every chord is a subset of several scales: any scale that contains all of a chord's tones fits over it. Pick a chord to see the matching scales from its own root, the major keys the chord belongs to, and full fretboard diagrams for every scale on guitar.
An Fm7b5 chord contains the notes F – Ab – Cb – Eb. Any scale that includes every one of those 4 tones fits over it — from the root F, that means F Blues, F Locrian, F Half Whole Diminished and F Gypsy Major. They differ only in the notes between the chord tones, and that is where each scale gets its color.
Fm7b5 is also diatonic to one major key: F# major (relative minor D#m). In a song from one of those keys you can also solo with the key's own major scale or its relative minor pentatonic across the whole progression, not just this chord.