1) As if by magic 2) Hauntingly 3) How banshees wail 4) How haunted houses creak 5) How Poe wrote 6) How zombies walk 7) In a chilling manner 8) In a creepy way 9) In a creepy, macabre way 10) In a macabre manner 11) In a macabre way 12) In a manner designed to chill 13) In a scary way 14) In a spine-tingling way 1) Spookily 2) Weirdly 
• (adv.) In a strange, unearthly way.
Ee'ri·ly adverb In a strange, unearthly way. 
[adv] - in an unnatural eery manner
spookily adverb in an unnatural eery manner; `it was eerily quiet in the chapel`